WASHINGTON • Police in Washington state are hunting for a gunman described as a "Hispanic male wearing grey", who opened fire in a mall, killing four women and critically wounding a man, who later died.

The suspect walked into the Cascade Mall in Burlington, Washington, about 105km north of Seattle, and began shooting on Friday night, Washington State Patrol spokesman Mark Francis said.

He left the scene before the police arrived and was last seen walking towards a nearby highway.

Mr Francis said police and rescue workers carefully worked their way through the 40,320 sq m mall, clearing stores and evacuating shoppers some of whom, according to local media, had locked themselves in dressing rooms.

A helicopter and search teams scoured the area for the shooter.

The local authorities continued their search yesterday for the gunman, believed to be armed with a rifle, and warned residents to remain inside.

Four women were killed in the attack in the mall's Macy's store cosmetics department. The fifth victim, a man, died in hospital.

Witnesses told KOMO News that the shooter walked into Macy's and opened fire.

"I hear one shot and then stand kinda still and, like, two, three other people start running out saying 'gun' and then shot after shot after shot," said Mr Armando Patino, a worker at a cellphone store.

"I turn around and run to the store. Some people didn't know where to go. I just moved them into the store.

"We went in the back where we have a door and everything and we just stayed there until they told us to evacuate."

The authorities believe there was only one gunman, but it was unclear whether he had help.

The Federal Bureau of Investigation (FBI), which is assisting in the investigation, said early yesterday that it had "no information to suggest that additional attacks" were planned in Washington state.

Ina statement issued on Friday night, state governor Jay Inslee said "tragedy has struck in Washington tonight".

"We urge residents to heed all safety and detour warnings. Stay close to your friends and loved ones as we await more information and, hopefully, news of the suspect's capture."

The shooting comes less than a week after a man stabbed nine people at a mall in central Minnesota before being shot dead. The FBI is investigating that attack as a potential act of terrorism.

NBC News reported Washington State Patrol as saying there was no indication of terrorism in the shooting in Burlington.

Nevertheless, the city in Skagit county remains gripped by fear.

"Cascade Mall still an active scene," the Skagit county emergency office tweeted. "Stay alert. Call 911 if you see anything."

REUTERS, NYTIMES, AGENCE FRANCE-PRESSE