(Reuters) - A violent altercation that escalated into gunfire in downtown Seattle left one woman dead and six other bystanders wounded outside a fast-food restaurant on Wednesday, and police said they were searching for at least two suspects.

The precise circumstances of the shooting, what precipitated the bloodshed and the number of people involved remained murky hours after the incident, which unfolded in a busy shopping district during the evening rush-hour.

The violence, which investigators deemed was “not a random incident,” grew out of a dispute in front of a McDonald’s restaurant, Seattle Police Chief Carmen Best told reporters at a briefing near the crime scene.

“People pulled out guns, shots rang out, people ran in various directions,” she said.

The chief added there were “multiple people involved as shooters” who apparently fled the scene, but she declined to specify how many suspects police believed were at large.

“We’ve locked down the scene. We have no active shooting at this point ... so everything is safe for the night.”

Seattle television station KOMO-TV, citing witness accounts, reported that two men were seen arguing on the street before pulling guns on each other and opening fire as pedestrians around them scattered for cover.

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All of those hit by gunfire were believed to have been bystanders, authorities said.

A Fire Department spokesman described the lone fatality as a woman about 40 to 50 years of age, who was found dead at the scene. Seven other victims were brought to Harborview Medical Center’s emergency room, a hospital spokeswoman said.

One of those patients was a woman in her 50s who was listed in critical condition as she underwent emergency surgery, according to Seattle Fire Chief Harold Scoggins. Another was a 9-year-old boy in serious condition, he said.

An office worker identified only as Bill told KOMO-TV he heard gunfire and saw scores of people running away in terror as he watched the scene unfold from an upstairs office window .

“It was sheer panic,” he said. “I’ve never seen anything like it.”

(This story corrects time element in paragraph 1 to Wednesday)