Officials said they were tipped off about an imminent attack in the southern German city shortly before midnight as Europe prepared to ring in the New Year in an atmosphere of unprecedented security.
European capitals have been on high alert since November when Islamic State jihadists slaughtered 130 people in a series of gun and suicide attacks in Paris, stoking fears they could stage further attacks over the Christmas and New Year holidays.
Just over an hour before the celebrations began in Munich, police ordered the evacuation of the city's main rail station and another station in the west of the city after being tipped off about a possible “terror attack.”
Police said an investigation was under way, with 550 officers deployed to hunt down the suspects and secure the city, warning that the threat remained “high.”
Munich police chief Hubertus Andrae said “five to seven” suspects were believed to be involved in planning a “suicide attack” as the festivities got under way.
German officials said they were tipped off by a “friendly intelligence service” about the plan, which was to have been executed at around midnight, said Joachim Herrmann, interior minister for the southern state of Bavaria.
-- Police warn via Twitter --
Police issued alerts via Twitter in several languages at around 10:40pm, and evacuated Munich's main rail station and another station in the western suburb of Pasing over what they called a possible “terror attack.”
Rail services at both stations were immediately suspended and police urged the public to avoid large gatherings. Both stations later reopened at around 3:30 a.m., but police urged the public to remain vigilant.
“We still have many colleagues deployed. There is as before a high threat of terror,” a police spokesman told AFP, saying the investigation was ongoing.
“The indications (of a possible attack) have not been substantiated so far, but we are taking them seriously and hence our (security) measures,” he said.
Regional broadcaster Bayerischer Rundfunk said the suspects were seven Iraqis living in Munich who were allegedly planning to work in pairs and blow themselves up at the two stations as well in other parts of the city.
Germany had been tipped off by both US and French authorities, it said.
Meanwhile, Munich police also thanked the public for “staying calm” in a series of tweets in both English and German.
Across Europe, public celebrations went ahead as planned but under the watchful eye of thousands of police and security forces.