It is not yet known whether the six cases are connected, but the modus operandi appears to be the same: A man on a bicycle rides up to a woman walking at night and sprays her with a liquid.
This is what happened to a 41-year-old walking late on Monday around midnight in the eastern Prenzlauer Berg district, police report.
The woman told police that a man rode by her and sprayed an as of yet unknown substance in the direction of her head. Police said that luckily the woman acted quickly to use her scarf to block the liquid from hitting her, meaning she was left unharmed.
The man then rode away, but the woman was able to give police a description: He was between 35 and 45 years old with light skin, of medium height and a strong-looking build.
He was wearing a black jacket, black trousers, a black baseball cap with a straight brim, and a dark belt bag. His bike is said to have a distinct handlebar.
Police told The Local that it is not yet known what kind of liquid the man used against the woman on Monday, but in four of the five other similar cases, the substance was identified as battery acid.
The first such cases were reported in December when three different women in the Prenzlauer Berg area and nearby Weißensee were injured after being sprayed by a man with a liquid.
One of the women said the cyclist may have used a water gun when he attacked her before midnight. She sustained light injuries and reported feeling burning pain to her face.
Just a few minutes later, another woman was sprayed by someone in the face and as a result went to a doctor.
The next day, a female pedestrian was also sprayed by a cyclist, then ran home to call an ambulance to receive treatment for her eyes.
In these three incidents, police described the man as having a thin build, a dark and wide jacket, and a beige-coloured hat. In at least one of these cases, the substance was identified as battery acid.
In January, a woman's face was slightly injured by a cyclist spraying liquid at her in Prenzlauer Berg at around 11pm. Police did not have a description of the suspect in this case.
"What happened at the crime scenes appears to be the same and we are investigating, but we cannot be 100 percent certain that it is the same person because we do not yet have him," the spokeswoman said.
The cases have naturally stirred up concern among some women in Berlin.
"This kind of situation is not something you can anticipate: the man comes up suddenly, attacks and then is gone," the spokeswoman said.
"There should not be panic now... We are doing all that we can to investigate and are searching for witnesses."