PITTSBURGH A man opened fire on officers responding to a domestic disturbance call this morning, injuring at least four of them, some seriously, before barricading himself in the home, police said.

Police were unable to reach one of the wounded officers, because the man in the house was armed and the area had not yet been secured, police spokeswoman Diane Richard said. One witness reported hearing hundreds of shots.

Richard declined to comment specifically on the extent of the officers' injuries.

The officers were called to the home in the Stanton Heights neighborhood at about 7 a.m., Richard said.

A family member was believed to be with the gunman in the home and police negotiators were trying to persuade the gunman to surrender, she said. State, county and city police were at the scene with a SWAT team and a state police helicopter.

Tom Moffitt, 51, a city firefighter who lives two blocks away, said he heard about the shooting on his scanner and came to the scene, where he heard "hundreds, just hundreds of shots. And not just once several times."

Rob Gift, 45, who lives a block away, said he heard rapid gunfire as he was letting his dog out.

He said the neighborhood of well-kept single-family houses and manicured lawns is home to many police officers, firefighters, paramedics and other city workers.

"It's just a very quiet neighborhood," Gift said.