Police gather at the site where four police officers were killed at the Forza Coffee Co. near Parkland, Wash., on Sunday. (Lui Kit Wong/The News Tribune/Associated Press)Four police officers have been shot dead at a coffee house south of Tacoma, Wash., in what authorities are describing as an ambush.

The uniformed officers were about to start their day shift and were sitting at laptop computers Sunday when a gunman entered the Forza Coffee Co. store and opened fire on them with a handgun, officials said.

Ed Troyer, a spokesman for the Pierce Country Sheriff's department, said investigators believe the officers were targeted, and it was not a robbery.

He told Tacoma's News Tribune newspaper, "It was just a flat-out ambush … This was an execution, no doubt."

Troyer said officers were looking for one male suspect who fled on foot and may have been wounded by one of the officers. He asked clinics and hospitals to report anyone who shows up with a gunshot wound. An accomplice hasn't been ruled out.

A crime scene investigator from the Washington State Patrol looks over the scene where the officers died in the Tacoma, Wash., suburb of Parkland on Sunday. (Robert Sorbo/Reuters)The officers — three men and a woman from the Lakewood Police Department — were attacked at 8:15 a.m. local time. Two of the officers were shot and killed as they sat at a table. Another one was shot standing up. The fourth officer fought with the gunman and made it outside and was able to get off some shots, Troyer said.

Investigators have talked to two employees and a few customers who were in the shop at the time. The baristas who were working there are "stunned and shocked, traumatized," Troyer said.

Streets around the coffee shop were blocked off late Sunday morning and a police helicopter hovered over a large crowd of investigators.

With files from The Associated Press