Four women were shot dead and one man died of his wounds after being airlifted to hospital following the attack at the busy Cascade Mall in the city of Burlington.

The man, who was in critical condition, “did not make it through the night,” police spokeswoman Heather Axtman said.

Sergeant Mark Francis of the Washington State Patrol tweeted about the alleged shooter, who was still at large, saying police believed there was just one gunman and that he was armed with a rifle.

Officials released a still from video surveillance of the younger-looking suspect holding what appears to be a rifle. Picture: Skagit County Department of Emergency Management

The suspect apparently left the scene at Cascade Mall on Friday evening before the police arrived. He was described as “a Hispanic male wearing grey”. Police did not comment on a possible motive behind the attack. Francis said four of the victims had been found at Macy’s, a department store. “We believe all five were found at Macy’s but it has not been confirmed if the fifth was yet,” he said.

A witness to the shooting, named Jo Zavala, said he “heard a lot of shots and people running out of Macy’s store.” “Then I saw a man pointing a gun and shooting people. And then I got up to go look and he saw me, pointed the gun and I took off running,” he told local broadcaster K5.

When he returned to the store to look for his wife, Zavala found some of the victims, including two elderly women, lying bleeding on the floor, he said. Francis said on Twitter that police were wrapping up a search of the shopping mall area and were “actively searching for the suspect.”

The Macy’s store at the Cascade Mall in Burlington. Picture: AP

Earlier, Francis tweeted that the gunman had left the scene before police arrived and police were sweeping the shops in the mall.

“EMS starting to enter to attend to injured inside Mall w/ police escort and after initial clearance,” Sgt Francis said on Twitter, referring to emergency medical services.

“Once EMS gets in, holding out hope that the number confirmed goes down.”

Police received calls around 6:58pm (0058 GMT) that shots were fired at the mall, Trooper Rick Johnson told CNN.

“Right now we can’t assume anything. So they’re still interviewing witnesses and trying to get a good idea of exactly what action to take next. We’re just asking people to, obviously, stay away from the area. Stay inside and obviously report anything suspicious that they may see.”

Witnesses described chaotic scenes in the wake of the shooting.

Stephanie Bose, an assistant general manager at Johnny Carino’s Italian restaurant near the Macy’s store, said she immediately locked the doors to the restaurant after hearing about the shooting from an employee’s boyfriend.

“He was trying to go to the mall and people were screaming,” she said. “It was frantic.”

Brandi Montreuil told CNN said she was at the movies when attendants told them to leave.

“I didn’t know anything,” she said. “The theatre attendant came in and apologised for stopping the movie and said they (staff) were asked to have everyone leave immediately.”

She said at first she thought it was a drill.

“But you immediately think about what happened in Aurora, Colorado (the 2012 cinema shooting that left 12 dead), so you start moving faster,” she said.

When they got outside she said an officer “with a large gun started yelling for people to leave, and fast.”

The Cascade Mall is an enclosed shopping mall that opened in 1990, according to the mall’s website. It features J.C. Penney, TJ Maxx, and Macy’s stores, among other stores, restaurants and a cinema.

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.

Washington State Patrol had reportedly said that there was no indication of terrorism in the shooting in Burlington.

“At this time, the FBI has no information to suggest additional attacks planned in WA state,” the agency said on Twitter.

More follows