A truck driver was arrested on Monday after trying to back out of a group of protesters who surrounded his rig.

The incident happened on October 23rd in Los Angeles County, California, near the Aliso Canyon natural gas storage facility.

The protesters gathered to stop business near the facility, which suffered a gas storage leak in 2015, that leaked methane into the air.

The owner of the facility, Southern California Gas Co., has since repaired the damage and after vigorous testing determined that the structure is safe and poses no risk to the air quality. Despite the assurances, the protesters gathered around the plant on Monday, shouting chants of “shut it down” and waving picket signs demanding that California Governor Jerry Brown order the closure of the facility.

After a few hours, a truck driver showed up to deliver a load to the storage facility but was blocked by protesters.

The truck driver then attempted to drive through the crowd but was stopped by the group of protesters, leaving the driver with no choice but to put the rig in reverse and back away.

Officers then arrested the truck driver on suspicion of assault with a deadly weapon using a vehicle.

18 additional protesters were arrested for failure to disperse after police declared the gathering an unlawful assembly.

Southern California Gas Co. says the facility undergoes the “most rigorous monitoring, inspection and safety requirements in the nation,” and that it is safe to operate.

The identities of the truck driver, as well as the protesters arrested, have not been released.