Developments On Wednesday:
- A Tunisian man has been identified as the prime suspect for the attack which killed 12 people and injured dozens more.
- Officials have confirmed he is called Anis Amri, is 24 years old and a Tunisian citizen. He could be armed and dangerous.
- Police are reportedly on the point of conducting an operation in North Rhine-Westphalia (NRW) in western Germany in relation to the Berlin attack. It seems that his is a search of a refugee centre where Anis A. once resided.
- The AfD are provoking centrist parties by blaming the attack on Merkel. They have called a silent vigil in front of her office.
6.17pm Tunisian anti-terrorism police were on Wednesday questioning the family of Anis Amri, the prime suspect in the deadly truck assault on a Berlin Christmas market, a security official told AFP.
"A unit of the anti-terrorism brigade has questioned the suspect's family," the official said, speaking on condition of anonymity.
The Tunisian security official said Amri's parents were being questioned. Amri has four sisters and a brother, the source said, but it was unclear if anyone else was being questioned.
The source said Amri had been arrested several times in Tunisia for alleged drug use.
He fled Tunisia to Italy after the 2011 revolution that overthrew longtime dictator Zine El Abidine Ben Ali and spent three years there before travelling on to Germany, the source said.
Contacted by AFP, Tunisia's interior and foreign ministries refused to comment on the case.
5.57pm Federal investigators (BKA) have now made the hunt for the suspect public. He is 24-year-old Anis Amri, a Tunisian citizen. They warn that he could be armed and dangerous. They are offering €100,000 for information that leads to his arrest.
He is described as being 178cm tall, with brown eyes and black hair. He weighs around 75kg.
4.30pm To summarize the events of the day so far and what they mean:
If various news reports about the suspect turn out to be true, the fact that this attack happened is not only a tragedy for the victims and their families, it could also turn into a political scandal.
Tagesspiegel and SZ have reported that the suspect should have been deported from the country months ago. It seems that he applied for asylum under different names and managed to get hold of temporary papers under one of his aliases.
The suspect was taken into custody pending deportation and then released a day later, according to SZ.
He had also already been a suspect in an investigation over a terror plot, but apparently fell off the radar after he moved from western Germany to Berlin.
If he turns out to be the driver of the truck - and his ID was found in the cabin - serious questions will inevitably be asked about how such a man was not stopped before committing this horrible crime.
An analysis piece we published yesterday argued that it is hard for the intelligence community to find lone wolves who are quickly radicalized. But there would be far less excuse for failing to prevent an attack by a man already on the state's radar for more than one offence, including a terror related one.
4.28pm France tightens security checks at German border with suspect still on the loose.
The French interior minister sent a memo to all local police authorities asking them “to take all necessary measures to strengthen controls at the Franco-German border, without delay.”
4.21pm Detectives in NRW had already investigated Anis A, on suspicion of preparing an act of terrorism, the state interior minister Ralf Jäger has confirmed.
German media have reported that Anis A. is being hunted for truck attack.
Since February Anis A. had lived in Berlin and police in the two states had exchanged information on the man, the last time being in November.
But at some point he seems to have fallen between the cracks of inter-institutional exchange, the SZ reports.
Jäger also said that "it is far from confirmed" that Anis A. was the driver of the truck
4.17pm Interior Minister Thomas de Maiziere has said police won't be releasing the suspect's name or pictures of him, despite the name of a Tunisian man already circulating widely in the press.
"It is important to us that we have success - therefore we will be searching undercover at first," he said.
Since midnight the man is being searched for across Europe, said de Maiziere.
3.47pm The interior minister in NRW, Ralf Jäger, has confirmed that the suspect was supposed to be deported back to Tunisia. However the case was held up because Tunisian authorities at first refuted that he was a citizen of their country.
"The necessary papers arrived from Tunisia today," SZ reports Jäger saying.
The SZ also reports that the suspect spent a day in detention but was freed again after authorities were not able to ascertain completely his actual identity.
3.06pm Interior Minister Thomas de Maiziere confirmed Wednesday that authorities have identified a new suspect in the case.
"There is a new suspect we are searching for - he is a suspect but not necessarily the assailant," he told reporters.
He declined to immediately confirm numerous media reports that the suspect was a Tunisian asylum seeker with links to the Islamic extremist scene.
However a conservative lawmaker at the same news conference, Stephan Meyer, said the suspect was in fact from Tunisia and being watched by police.
"We are apparently talking about a potentially dangerous suspect who was known to authorities and belonged to the Salafist-Islamist scene," he told reporters after a meeting of parliament's interior affairs committee.
Meyer, of Chancellor Angela Merkel's Christian Democrats, said the case underlined his party's drive to see Tunisia, Morocco and Algeria as "safe countries of origin" whose citizens would not normally be granted asylum.
Media reports said asylum office papers believed to belong to the Tunisian man were found in the cab of the 40-tonne lorry used in the attack that killed 12 people.
Germany this year moved to declare Algeria, Morocco and Tunisia as safe countries of origin, to raise the bar for asylum requests after last year's record influx of around 890,000 people.
But the bill has been stuck in the upper house for months over human rights concerns in those countries.
2.51pm Tagesspiegel is reporting that the Tunisian man whom police are currently pursuing should have been deported long ago and that several attempts to deport him failed.
The newspaper claims that he had an asylum request rejected in the summer of 2015. It also reports that the temporary papers belonging to him which were found in the truck were filed under a different name.
If this proves to be the case it will add fuel to an already tinder-charged debate on deportations and abuse of the asylum system.
In several high profile crimes this year, the suspects should have already left the country. This was the case for the man who carried out a suicide attack at a bar in Ansbach in July.
It was also true of a rape suspect arrested in Hamburg earlier this month. The Moroccan suspect should have been deported from Lower Saxony, where several thousand people with deportation orders are still living in the state.
Questions will also be asked about how a man who had an asylum request rejected could have then received temporary papers under a different alias.
2.32pm According to a poll by broadcaster RTL and polling firm Forsa, 80 percent of Germans feel safe despite the attack.
Ten percent of respondents said they would not attend big public events out of fear of an attack; 46 percent said they'd go but they'd be worried; 43 percent said security fears would not concern them.
A slight majority (51 percent) said current security measures are adequate for protecting the country
2.28pm Berliners have gathered with refugees at the site of the attack in Breitscheidplatz to send out a signal of solidarity. Signs such as "you will not divide us" were held up, while the crowd sang Silent Night and We are the World, reports Die Welt.
2.14pm Federal investigators (BKA) have confirmed a hacker attack on their "leads" website.
On Tuesday between 5pm and 7.30pm the site crashed and members of the public were not able to provide investigators with evidence such as video footage which could help their enquiry, Spiegel reports.
The BKA say it was a DDoS attack, which crashes servers by overloading them.
2.04pm The interior minister of NRW is set to give a press conference at 3.30pm. Police are following a lead in the area with an operation reportedly imminent. The suspect is known to have stayed at a refugee home in the town of Emmerich in the northwest of Germany's most populous state.
12.58pm The Christmas market in Breitscheidplatz is set to reopen on Thursday, only three days after the attack, according to the federation of festival organizers.
All other Christmas markets in the capital opened again on Wednesday after being closed on Tuesday.
Across the country police have heightened security at Christmas markets, including putting concrete blocks in front of the entrances. Markets and Christmas events across Europe have also seen security measures ramped up, including in Italy, France and Norway.
12.31pm The attack has led to hefty infighting within Germany's government, with the Bavarian CSU threatening to split away from Merkel's CDU after next year's elections if its demands are not fulfilled.
The CSU has linked the attack to the government's refugee policy, while the CDU has been very careful about making any connections before charges have been pressed against a specific individual for the attack.
CSU leader Horst Seehofer says his party will pull out of the government after next year's election if there is no deal on an upper limit on refugees in the coalition agreement. This has been a repeated demand of the CSU, despite the fact the government has brought refugee numbers down to a trickle through various measures including a send-back deal with Turkey.
12.26pm The far-right AfD have called for a silent vigil in front of Angela Merkel's office in Berlin. Leading figures in the party including Alexander Gauland and Björn Höcke are set to attend.
Höcke wrote on Facebook: "Enough is enough! Show your faces in Berlin."
The AfD have been accused by opponents of using the deaths in Berlin for political purposes.
Before a suspect was identified, leading figures in the party on Monday had laid the blame for the attack on the door of Merkel's refugee policy.
12.15pm A report in Bild suggests that the Polish man found dead in the passenger seat of the truck may have prevented a higher death toll.
The tabloid claims to have talked to people familiar with the postmortem who say that he was shot after the rampage.
The body reportedly shows the signs of a fight suggesting that the man, who was the driver of the truck before it was taken over by the attacker, tried to grab the steering wheel away from the attacker.
12.02pm The Süddeutsche Zeitung is reporting that the suspect received permission to stay in Germany in April, but that he was classified as "dangerous" by authorities.
He was under observation and had links to Islamist preacher Abu Walaa, but went underground this month, writes SZ. According to this report he has 8 different identities, one of which he used to apply for asylum.
In November police arrested Abu Walaa along with four other men who are considered to be key links to Isis in Germany.
According to Süddeutsche Zeitung (SZ) information, authorities have long considered Abu Walaa, to be one of the central figures in the German Islamist scene and have described him as "the faceless preacher."
Abu Walaa and his circle have already been linked to a bomb attack on a Sikh temple, which took place earlier in the year. That link has as yet not been proven in court.
11.48am Bild reports that he had several passports, was aged 21-23, known to police for grievous bodily harm. They cite an unnamed source.
11.42am Police in North Rhine-Westphalia are preparing "immediate actions" in connection with the Berlin attack, reports DPA.
11.30am The man is reportedly called Anis A. and was born in 1992 in the city of Tataouine.
The identification, a so-called Duldungsbescheinigung - a document giving the man permission to stay in Germany without granting him asylum - was reportedly found under the driver's seat of the truck.
Police have asked federal prosecutors for permission to conduct a nationwide search. Federal investigators are set to give a press conference at 1pm.
On Monday evening a man drove a large truck into a Christmas market in west Berlin killing at least 12 people and injuring almost 50 others. The attacker escaped the scene before police could catch him.
Isis have claimed responsibility for the attack, saying that the perpetrator followed their call for adherents to attack the countries which are fighting against them in the Middle East.
Isis have not provided evidence they were directly involved in the attack.