Officials say a group of pro-Palestinian protesters are again blocking an Israeli-owned commercial ship from unloading its cargo at a port in California.

International Longshore and Warehouse Union spokesman Craig Merrilees says longshore workers did not unload cargo from the Zim Shanghai docked at the Port of Oakland on Saturday morning because of safety concerns raised by the presence of police and protesters.

Steve Zeltzer, a spokesman for the Stop Zim Action Committee, says about 200 protesters planned to demonstrate again during the longshore workers’ evening shift.

The protesters are demonstrating in response to Israel’s recent Operation Protective Edge, which targeted Gaza-based terrorist groups firing rockets and mortars against Israeli civilian communities.

Last month, protesters blocked cargo from unloading off the Zim Piraeus for nearly five days before the ship apparently departed to Los Angeles with a partial load.