John Bacon | USA TODAY

AP

Meiying Wu, AP

Leaders and residents across Boise have been voicing strong solidarity with the city's refugee population after a knife-wielding attacker slashed nine people, including six children, at a birthday party Saturday in Idaho's capital.

Boise Police Chief William Bones said the children ranged in age from 3 to 12. All of the victims are from Syria, Iraq or Ethiopia.

"This was an attack on those who are most vulnerable – our children,” Bones said. “It’s untenable, unconscionable and is pure evil in my mind.”

Children who witnessed the attack outside an apartment complex that is home to families from around the world said they ran and hid in a closet.

“We saw a killer. We didn't want to get stabbed,” 12-year-old Esrom Habte said. "We saw him saying bad words (and stabbing an adult) really hard and a lot of times."

More: 6 children among 9 people wounded in knife attack in Idaho

Esrom said he gathered two sisters and two other kids into the closet, locked the door behind them, then called 911.

"We were waiting until they told us they caught him and then we went outside," he said.

Bones said the suspect, identified Timmy Earl Kinner of Los Angeles, was taken into custody within minutes, not far from the scene. Kinner, 30, was booked into the Ada County Jail on nine counts of aggravated battery and six counts of injury to a child.

Community groups have been raising money for the victims, and a candlelight vigil was planned Monday night.

Mayor David Bieter said the "senseless acts of one disturbed person" does not reflect the attitudes of city residents.

"Our city has long stood as a welcoming city, a place of safety and kindness for those fleeing violence and oppression in their homelands," he said. "As Boiseans, we come together not only to condemn this vile act but also to embrace those among us seeking refuge from tyranny, suffering and war.

"It is who we are and who we will continue to be."

Julianne Tzul, executive director of the International Rescue Committee in Boise, said her group was working with to provide counseling and support to refugees and other members of the community affected by the incident.

She lauded the "tremendous welcoming nature" of the Boise community since her group was established in the city 12 years ago. She said refugees in Boise are fleeing violence and persecution in nations around the world.

"It is heartbreaking to see people and children, who fled horrors of war and conflict to find safety in America and the Boise community, experience this violence all over again," she said.

A prayer gathering at the Imam Hussain Islamic Center on Sunday drew hundreds of supporters. Dozens of people stopped by the apartment building, some hoping to check on people they know.

"The one thing that I could do is show my presence and solidarity with these guys," said Lila Cabrera, a teacher who works with adult refugees. "These guys are survivors. That's why I teach them, that's why they give me the energy I have when I teach them. That's why I'm here."

A makeshift memorial of flowers and messages of support was growing at the apartment complex.

"People got hurt, and it's not OK," said Donna Hale, who brought flowers. "We just need to be there and say 'we don't know you, but we're on your side and that's what matters.'"

Bones said Kinner had met and then stayed with a resident of the apartments for a few days within the last week. The resident and some neighbors became concerned with the suspect’s behavior and asked him to leave Friday, which he did peacefully.

The suspect then returned to the apartments on Saturday and began attacking children, including the 3-year-old girl who was the focus of the party. He said Kinner did not appear to have any prior relationship to the partygoers, calling the attack a simple act of "vengeance."

"The crime scene, the faces of those parents struggling, the tears coming down their faces, the faces of the children in the hospital beds will be something that I'll carry with me for the rest of my life," Bones said.