The Washington State Patrol wants to know who threw the rocks and bricks that hit at least four cars on Seattle freeways Sunday, and in one instance smashed through a windshield.

The rocks and bricks struck cars at two places: Interstate 90 at 18th Avenue, and Interstate 5 at 12th Avenue.

Only minor injuries resulted from the brick that hit the windshield. It was the latest incident in a series of debris-throwing episodes, 186 in all, that have hit vehicles along Seattle freeways this year. The WSP has made several arrests to date but the incidents continue.