LOS ANGELES (AP) _ A freeway overpass collapsed during rush hour, dropping debris that blocked traffic for about five hours but causing no injuries, police said.

''It's a mess out there,'' California Highway Patrol Officer Lujuanna Lopez said after the collapse created a massive traffic jam about 10 miles south of downtown.

No injuries were reported when portions of the Harbor Freeway bridge collapsed about 6:30 p.m. Monday, said CHP Officer Charlotte Foley. Northbound vehicles were re-routed to streets until California Department of Transportation workers cleared the debris about five hours later, police said.

The overpass, which was under construction, apparently shifted on its base, a transporatation department dispatcher said. Engineers investigated the cause of the slippage. Damage estimates were not immediately available.