Philly police were investigating Sunday how a woman ended up slashed with a shattered bottle by another female at local bar early Sunday.

The victim, 37, was inside Fiddler's Green Tavern on the 7300 block of Frankford Avenue in Northeast Philly dancing with a patron around 2 a.m. when a woman who she knew approached her, police said.

The suspect allegedly "struck her in the head with a beer bottle and then continued swinging the bottle cutting the [victim] on the face and neck," the police report stated.

The victim suffered a severe face and neck laceration and required emergency surgery, police said. She was listen in critical condition at Aria Torresdale Hospital.

The alleged attacker is known to police and has a criminal record, but has not yet been arrested while the investigation continues.