Stena Line has cancelled four sailings between Scotland and Northern Ireland after one of its crew members tested positive for Covid-19.
The positive test result has impacted on its Belfast route to and from Cairnryan.
In a statement, the company said its 7.30pm departure from Cairnryan and 11.30pm departure from Belfast were cancelled on Wednesday.
The same incident also led to the company calling off its 03.45 BST departure from Cairnryan and its 07:30 BST departure from Belfast on Thursday.
Stena Line has apologised to passengers for the inconvenience but said it had acted in accordance with its "comprehensive safety protocol procedures".
The company confirmed that the crew member received a positive result from a lateral flow test (LFT).
The employee and four other crew members, who were identified as close contacts are all now self-isolating, while the rest of the crew are undergoing Covid-19 testing as a further precaution .
The firm added: "Stena Line is currently working with the local and port health authorities in Scotland in a bid to restore the service as quickly as possible, adhering to all prevailing public health safety protocols."
