Someone threw an unknown liquid on a traffic enforcement agent in Park Slope Wednesday in the middle of her shift.

It happened around 11:45 a.m. near the corner of Seventh Avenue and Sixth Street, according to the NYPD.

Police say the 33-year-old woman was working in uniform when a man came up and suddenly splashed her with a liquid—then drove away in a 2014 Infiniti sedan, heading west on Sixth Street.

The agent was taken to New York-Presbyterian Brooklyn Methodist Hospital as a precaution. Sources tell News 12 the liquid didn’t burn her skin, but that it caused serious concern since no one knew what it was.

The attacker hasn’t been caught, and police are still trying to figure out what exactly was in that bottle.

If you saw anything or have information, you're asked to contact the NYPD.