Since the strike began on October 26, only two of the four daily scheduled trips have been running because of a shortage of staff, the Robben Island Museum said in a statement.

All the ferries were canceled on Saturday, when strikers briefly occupied one of the boats and prevented tourists from boarding. Police finally removed the workers, it said.

“Robben Island Museum would like to apologise to all its stakeholders for the inconvenience which has been caused by the on-going strike,” museum chief Sibongiseni Mkhize said in a statement.

“We would like to assure our visitors, tour operators and members of the public that services have been restored and Robben Island Museum managed to continue running their tours on Sunday.”

The workers want across-the-board increases of 2,000 rands ($250, 180 euros) and for the island to close in peak tourism season from December 25 to January 2 so they can spend time with their families.