People gather inside and outside a fence Thursday during a rally at a park in Olympia, Wash. Two stepbrothers suspected of trying to steal beer from a grocery store were shot Thursday by a police officer after he confronted them and reported he was being assaulted with a skateboard.

OLYMPIA, Wash. — Hundreds marched peacefully in Washington state’s capital city to protest a police shooting that wounded two unarmed stepbrothers suspected of trying to steal beer from a grocery store.

The officer reported he was being assaulted with a skateboard early Thursday before the shooting that left a 21-year-old man in critical condition and a 24-year-old man in stable condition. Both were expected to survive.

The stepbrothers are black, and the officer is white, but Olympia Police Chief Ronnie Roberts said, “There’s no indication to me that race was a factor in this case at all.”

Protesters who turned out Thursday evening held signs that read “Race is a Factor” and “We Are Grieving.”

The two men were identified as Andre Thompson, 24, and Bryson Chaplin, 21, both of Olympia.

“It was terrible,” the young men’s mother, Crystal Chaplin, said. “It’s heartbreaking to see two of my babies in the hospital over something stupid.”

The shooting is being investigated by a team of detectives from several agencies. Brad Watkins, chief deputy of the Thurston County Sheriff’s Department, said two skateboards were recovered from the shooting scene and an investigation will likely take three to six weeks. The young men had no guns, investigators said.

The crowd of demonstrators rallied first at a park, then marched about a mile to a building that houses the Olympia police headquarters and City Hall. Protesters chanted “Black Lives Matter,” “No Justice, No Peace” and the names of the young men who were shot.

Olympia police tweeted their thanks to marchers “for keeping the event nonviolent.”

“We are committed to helping our community work through this difficult circumstance and help us understand this tragic event,” the police chief told a news conference.

Officer Ryan Donald was among those who responded around 1 a.m. Thursday to a call from a Safeway store, Roberts said. Employees said two men tried to steal beer and then threw the alcohol at workers who confronted the pair.

Officers split up to search for the men. Donald encountered two men with skateboards who fit witnesses’ descriptions, and moments later he radioed in that shots had been fired, the police chief said.