Four police officers have been shot dead near the McChord Air Force Base in Washington State, US media and police say, BBC reported.
A sheriff's department spokesman told KOMO-TV that the officers were shot at the east side of the air force base.
The officers were fired on while they were at a coffee shop, police say.
A sheriff spokesman described the shooting as an ambush. The air force base is in Parkland, Pierce County, 40 miles south of Seattle.
Pierce County Sheriff's spokesman Ed Troyer told local media that the officers had been in the coffee shop with their computers when the shooting happened on Sunday morning.
He said it is believed that the officers had been targeted and the incident was not a robbery.
Officials at the scene said two suspects had opened fire, KOMO-TV reported.
Other customers were in the coffee shop at the time but no-one else was injured, the report said.
The area has been sealed off by police.