Deadly shooting at Oregon mall
One other person was seriously injured at the Clackamas Shopping Center and taken to hospital, Lt James Rhodes of Clackamas County Police Police said.
Mall entrances were blocked, and police said the suspect was "neutralised" before confirming his death.
Dozens of police and emergency medical teams remain at the scene and a search is ongoing, Lt Rhodes said.
The shooting began at about 15:30 PST (23:30 GMT) in Clackamas, a suburban town on the southern fringe of Portland, in the middle of the Christmas shopping season, Kazinform has learnt from BBC.
Witnesses said the gunman opened fire several times while on the second floor of the shopping centre, near the food court and Macy's department store.
Police have recovered a gun, but said they were still searching the mall for any other evidence, as well as anyone who had locked themselves inside a store during the alert.
"We know of several groups of employees that have locked themselves in break rooms and bathrooms," Lt Rhodes said. "One at a time, very carefully, we are addressing each of those groups."
Taylor Gibson, a employee at Build-a-Bear, said when she first heard the shots, she and others rushed customers to the back room and closed the store's front gate.
"That gate takes 30 to 45 seconds to close," she told the Oregonian . "Honestly, as I was shutting that gate I was waiting for that person to walk up the hallway and shoot me."
Multiple witnesses reported to local media that the gunman was wearing a mask and brandishing an assault-style rifle.
Evan Walters, who worked at the mall and was locked inside a store, told local broadcaster KATU he saw two people who had been killed, and he and other store employees placed sheets over the bodies.
In a statement, Oregon governor John Kitzhaber said: "my thoughts and prayers are with the victims and their families... I have directed State Police to make any and all necessary resources available to local law enforcement".
