Westbound Interstate 80 near Hercules closed due to police activity

All westbound lanes of Interstate 80 in Contra Costa County are closed Thursday morning due to police activity, authorities said.

Caltrans said around 9:10 a.m. that westbound I-80 is closed at the Hercules offramp, leading to a backup that is stretching several miles to the Carquinez Bridge. Meanwhile, the left lane of eastbound 80 is closed at Pinole Valley Road.

According to the California Highway Patrol, the alert stems from an earlier traffic collision. 

Additional details about the incident were not immediately available.

Westbound traffic is being diverted at Willow Avenue, officials said. There is no estimated time to reopen the lanes and drivers are being urged to find alternate routes.