PITTSBURGH (AP) — Police say a man fatally stabbed a woman who was talking to an officer at a downtown Pittsburgh bus stop and slashed another woman before he was taken into custody.

Pittsburgh Police Chief Scott Schubert says the officer was checking on the woman's health just after 11:30 a.m. Thursday when a man came up from behind him and stabbed her. The suspect then stabbed the other woman.

Schubert says the officer immediately put the man in custody and applied first aid to the victim.

The sidewalks were crowded with office workers and others heading out to lunch.

Cmdr. Victor Joseph says the first woman died at a hospital. The second victim had minor injuries.

A motive isn't yet known, but he says it seems like a random act of violence.

No other details are available.