According to police, the 27-year-old woman was walking in the eastern district of Friedrichshain late on Monday night when an unknown cyclist sprayed her in the face with a liquid, which fire services said was acidic. The exact substance is not yet known.

The woman told police that the male cyclist was dressed in dark colours, and had continued biking after the attack.

The woman went to hospital to be treated for serious damage to her eyes, according to local broadcaster rbb.

This was the fifth such case reported since December last year. In January, another 27-year-old woman in the eastern Prenzlauer Berg neighbourhood was also attacked by a male bike rider in a similar way.

In December, a cyclist attacked three women with a skin-irritating liquid. In at least one of these attacks, the substance was found to be battery acid.

Police are now investigating whether there is a connection among the cases.