All westbound lanes opened on the San Francisco-Oakland Bay Bridge just before noon Thursday, California Highway Patrol said. Throughout the morning commute, protesters fully shut down westbound traffic as world leaders gathered in San Francisco for the Asia-Pacific Economic Cooperation summit.

Approximately 50 protesters were arrested and 15 cars were towed, CHP said. California Highway Patrol officer Art Montiel said 100 to 200 protesters associated with the activist group Arab Resource and Organizing Center were on the bridge earlier this morning. Video footage and photos posted on social media indicated that AROC is calling for an Israel-Hamas ceasefire.

Protesters drove onto the Bay Bridge and parked their cars just east of Treasure Island, bringing westbound traffic to a complete standstill around 8 a.m., CHP said. As of 10:15 a.m., the right shoulder was open to cars, and Montiel said lane No. 1 was expected to open in the next 20 minutes.

"It’s going to take a little while to have it fully open, at least another hour or so at the very least," Montiel said.

AROC posted images of the protest on social media. “@POTUS could end the genocide in #Gaza TODAY,” a message from AROC read. “Instead he’s using our tax $$ to pay for it and hosting cocktail parties in the SF Bay Area.”

CHP officer Miguel Camarena wrote in an email to SFGATE that "protestors were chaining themselves to each other and through their vehicles." Photos showed protesters holding massive banners across roadways, while videos show the protesters chanting, “Cease-fire now.”

Demonstrators shut down the San Francisco Oakland Bay Bridge in conjunction with the APEC Summit; Motorists wait in a queue as demonstrators shut down the San Francisco Oakland Bay BridgeNoah Berger/AP Demonstrators shut down the San Francisco Oakland Bay Bridge in conjunction with the APEC Summit; Motorists wait in a queue as demonstrators shut down the San Francisco Oakland Bay BridgeNoah Berger/AP

This same group gathered at the Port of Oakland on Nov. 3 to block the entrance to a ship they claimed was transporting weapons to Israel.

The protest has created a massive backup throughout the East Bay. According to 511.org, I-80 was gridlocked all the way back to the Albany exit. The Richmond-San Rafael Bridge has also experienced a severe backup stretching close to the Regatta Boulevard exit in Richmond.