Gunfire strikes cars on highway in Washington state

No injuries were reported in the incident, which happened Wednesday evening on State Route 509, Washington State Patrol said.

Some parts of the highway were briefly shut down as authorities searched for the shooter using K-9 units. Authorities released images of the cars hit by gunfire and said investigations are ongoing.

"Troopers and WSP aircraft are currently searching the area for the active shooter," Washington State Patrol tweeted late Wednesday. "Please remain vigilant and avoid the area ... If you see any suspicious activity, please call 911."