(CNN) Timmy Kinner wanted revenge for being kicked out of an Idaho apartment complex, police say.

So Kinner attacked a 3-year-old's birthday party at the complex, which houses refugees, and stabbed nine people, including six children, Boise Police Chief William Bones said Sunday.

Kinner has been charged with nine counts of aggravated battery and six counts of injury to a child, Bones said.

Four victims have life-threatening injuries, authorities said. Six are between 3 and 12 years old.

They were "some of the newest members of our community," Bones said, and included refugees from Syria, Iraq and Ethiopia.

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