LOS ANGELES - The California Highway Patrol is pursuing a white van on the 405 Freeway in the Irvine area in Orange County Monday afternoon.A passenger earlier jumped out of the van.The pursuit suspect has been driving off and on the 405 Freeway and traveling on surface streets, particularly on Harbor Blvd in the Garden Grove area.A gun was thrown out the window of the white van earlier in the pursuit.It's unclear what triggered the chase, which reportedly started in Garden Grove, California.