SAN FRANCISCO (KRON) -Traffic has cleared on the Bay Bridge after protesters shut down all lanes of westbound Interstate 80 traffic during the Thursday morning commute. The protesters stopped their cars on the bridge, east of Treasure Island Road, and threw their keys into the Bay before chaining themselves together and to the bridge, according to California Highway Patrol.

Around 50 to 60 protesters on the bridge were arrested and processed by responding CHP officers before being led to awaiting buses, according to KRON4’s Will Tran. Approximately 250 officers are on scene, according to CHP.

As of 10 a.m., a far-right lane of westbound traffic reopened on the Bay Bridge for motorists already on the bridge. Drivers who were backed up before the toll plaza were being guided by CHP to turn around back into Oakland.

During a news conference, the CHP said that protesters abandoned their vehicles on the Bay Bridge and threw the keys into the Bay. Fifteen vehicles have been towed from the bridge as of 9:45 a.m., and the CHP estimates another 5 to 15 more vehicles will need to be towed.

Protest organizers are calling for an immediate ceasefire and to end U.S. military aid to Israel, according to a press release.

Caltrans is encouraging motorists to use I-580, I-880, and Highway 92 as alternate routes. Transbay bus lines were being diverted to the West Oakland BART station for riders to continue into San Francisco via train, according to AC Transit.