Boys charged over rock-throwing incidents

Two boys, including one aged 12, have been charged over throwing rocks at cars travelling on a freeway in Perth with police alleging 13 vehicles were damaged.

Police say six of the vehicles were struck during the afternoon on Thursday and seven later the same night.

All were driving along the Mitchell Freeway at Kingsley in the city's north.

"In total, 13 people reported their vehicles were damaged while they were driving, with most reporting that rocks or unknown objects had struck their vehicle," police said in a statement.

It's believed all were damaged as they passed under the Hepburn Avenue overpass.

The boys were arrested nearby after the second series of incidents.

A 15-year-old from Kingsley and the 12-year-old from Quinns Rocks were each charged with 13 counts of acts causing bodily harm or danger.

They will appear in Joondalup Children's Court on January 31.

Police have appealed for anyone else who may have had their car damaged in the area to come forward.