Six teenage boys escaped from a juvenile detention center in Washington state after knocking out a female staff member, but all were captured a few hours later early Sunday in nearby woods, authorities said.

The King County Sheriff's department said it received word of the escape about 11:30 p.m. Saturday from Echo Glen Children's Center in Snoqualmie, about 25 miles east Seattle.

"They basically attacked the staff member, knocked her out, took her keys and fled," spokeswoman Cindy West said.

The six males ranged in age from 15 to 17 and were serving time for offenses including assault, possession of firearms and burglary, she said.

Law officers on the ground with search dogs and in the air combed the area on the outskirts of Snoqualmie before a helicopter crew spotted them in woods near the center, according to West. All were caught by 2 a.m. Sunday.

"The biggest reason they were apprehended so quickly was the helicopter," she said. "Without that we would have been looking for needles in a haystack. It allowed us to apprehend them before they got into the neighborhood."

West said her details on how the arrests came about were still sketchy, but she had no early word of any injuries.

She says the staff member suffered a non-life threatening injury to her head.