A masked gunman killed two people and wounded another at a crowded mall outside Portland, Oregon, before turning the gun on himself, authorities said.

The shooting at around 3:30 p.m. Tuesday sparked panic at the Clackamas Town Center shopping mall.

In a press conference, Sgt. Adam Phillips of the Clackamas County Sheriff's Office said police had tentatively identified the suspect, although they refused to provide a name until the information had been fully confirmed.

Several witnesses told CNN about the chaos inside the mall, in which employees and customers flooded outside the two-story building while others hid inside the stores.

They said several gunshots were heard near a spot where families with young children were waiting in line to take photos with a man dressed as Santa Claus.

The sheriff's office's Lt. James Rhodes said roughly 100 local, state and federal police were dispatched to the mall to inspect it store-by-store and help with the evacuation.

He said a lone gunman was responsible for the shooting.

According to media reports, the assailant was wearing a white hockey mask and a bullet-proof vest and was carrying an assault rifle, although Rhodes refused to confirm that information.

Clackamas County Sheriff Craig Roberts said in a press conference that the situation was under control at the mall, one of the largest and busiest in the Portland area. He said some 10,000 people were inside at the time of the shooting. EFE