TACOMA, Wash. -- Two men posing as plain clothes police officers have struck again, this time raping a Wendy's employee, Tacoma police said.

SLIDESHOW: Fast Food Robbers Caught On Camera

Officer Mark Fulghum said the two men pulled the woman and a male companion over at 2:20 a.m. Sunday, after following the car from a Wendy's fast food restaurant in Lakewood that had just closed for the night.

The men used a light bar with flashing red and blues lights, telling the victims they were checking out a stolen car report. Instead, said police, the male was assaulted and forced into the car's trunk at gunpoint.

Investigators said that when the woman told the men she could not get them back inside the Wendy's restaurant they intended to rob, they instead drove her to a wooded area and raped her.

It's not clear at this time how the woman and her companion escaped.

Police said the method of the robbery and the description of the men involved match those of similar robberies in which fast food managers are followed home, stopped in what appears to be a police traffic stop, kidnapped and then forced to return to their place of business while at least one of the men robs makes them over safes and cash boxes at gunpoint.

The pair is also believed responsible for a robbery at a McDonald's in Lakewood on Oct. 1, a Wendy's in Tacoma on Oct. 23 and a Burger King in Graham on Oct 25.

The two have used two vehicles: a newer, dark SUV and a black Honda or Nissan sedan with red and blue lights on the dashboard.

Both men are white, 20 to 25 years old, about 5 feet 8 inches tall and weigh 150 to 190 pounds.

Crimestoppers is offering a reward of up to $1,000 for information leading to the arrest of the men involved. Anyone with information should call 253-591-5959.