Five thugs knocked a teenager to the floor, threw bleach in her face and slashed her in a Bronx apartment building, cops said Tuesday.

Three men and two women confronted the 19-year-old woman just before midnight Monday on the first floor of a building at Aqueduct Avenue West and West 190th Street in Kingbridge Heights, according to police.

The squabble turned violent when the attackers, who were known to the teen, began punching and kicking her.

After bleach was thrown at her, one member of the group pulled out a blade and slashed her on the left side of the face, police said. She was taken to Montefiore Hospital with minor facial injuries.

Police arrested Sarina Murray, 21, at her home at around 1 a.m. Tuesday after, a source said, the victim identified her. She was charged with assault, menacing, criminal possession of a weapon and harassment.

The four other assailants were still at large Tuesday.