Three lifeboats have been launched to help a P&O ferry that has developed a “mechanical issue” in the Irish Sea.
The European Causeway “lost all power”, the RMT union said.
It is currently five miles off the coast of Larne, according to tracking website Marine Traffic.
P&O tweeted that tugs from Larne and Belfast had been deployed to the vessel and that a full inspection would take place.
The Maritime and Coastguard Agency only released it from detention on 8 April after a reinspection.