Seattle police searched for clues Sunday in a shooting that killed a police officer and injured a trainee, marking the city's first officer killed in the line of duty since 2006.

Assistant Police Chief Jim Pugel said a male officer was training a female student officer in a marked patrol car Saturday night when their vehicle was suddenly struck several times by gunfire, shortly after 10 p.m.

Pugel said a light-color car pulled alongside the parked police cruiser and began shooting in the mostly residential Central District, east of downtown Seattle.

The male officer was struck and killed in the car. The student officer ducked, then returned fire, Pugel said.

"The officer was murdered," Pugel said.

The police withheld the names or ages of the two officers until family members could be notified.

The student officer suffered minor injuries.

The investigation continued through the night. Early Sunday, Pugel said officers did not have a suspect or a suspect vehicle.

A news conference was tentatively scheduled for Sunday afternoon.

In August 2006, rookie officer Joselito Barber was killed when a woman drove her sport utility vehicle through a red light and broadsided his patrol car.