One person was killed and seven others were injured after a gunman opened fire at a Philadelphia graduation party Sunday night.

Four of the victims were teens between the ages of 15 and 17 who mostly suffered from gunshot wounds to their legs, Philadelphia Police Commissioner Richard Ross told reporters Sunday night.

ADVERTISEMENT

Four other adults, who suffered gunshot wounds to different areas of their bodies, are believed to be in their 20s. One of the adult victims was pronounced dead at the hospital, Ross said.

About 60 people were at the party when the shooting began.

It isn’t clear if there was more than one shooter, and Ross said the incident didn’t appear to be provoked by any sort of fight.

As of Monday morning, police had not announced any arrests in the shooting.