A gunman opened fire at a pool area of a San Diego apartment complex Sunday evening, killing a woman and injuring six other people, Police Chief Shelley Zimmerman said.

The gunman, Peter Selis, 49, shot all seven at the La Jolla Crossroads apartments around 6 p.m. before police officers fatally shot him, Zimmerman said.

Besides the seven who were shot, an eighth person broke his arm while fleeing the gunfire, police said. Zimmerman initially said that eight people had been shot.

A large group of people were celebrating a birthday party when the shooting began, Zimmerman said.

The victims' names were not immediately released.

Some of the injured were in critical condition late Sunday night, Zimmerman said.

It's unclear how many people were at the pool at the time of the shooting.

The gunman appeared to be reloading his large-caliber handgun when three officers arrived at the scene.

Police said they believe the gunman and at least one of the partygoers lived at the apartment complex.

"We don't know if he knew any of the victims," Zimmerman said.