The family and friends of a missing 38-year-old man have issued an urgent appeal for help locating him.
George Brennan, from Co Mayo, was last seen on Wednesday 2 April in Ballycastle, Co Antrim, and has not been heard from since.
The last known sighting of Mr Brennan was on CCTV in a Spar shop on Moyle Road in the town.
The footage shows him wearing a black zip-up top, dark jeans and runners. He is also carrying a blue hiking backpack.
Mr Brennan is 1.9m (6'2), 100kg, with brown hair and blue eyes.
It is believed that he may have travelled onwards from Ballycastle, by foot, hitchhiking or public transport.
In a statement, the Police Service of Northern Ireland said Mr Brennan "may have links to the Causeway Coast and Glens area" of Antrim, and "also the mid and east Antrim area".
He is an avid sea swimmer and hiker and there is concern he could have run into trouble doing these activities.
The PSNI are assisting An Garda Síochána and have issued an appeal for anyone with information to contact the police.
Mr Brennan's family and friends said they are deeply concerned for his wellbeing, adding that his disappearance is completely out of character.
Speaking on behalf of the family, a spokesperson said: "We are heartbroken and desperate for any news.
"George is deeply loved, and we just want to know that he is safe."
The spokesperson urged anyone who may have seen Mr Brennan, spoken with him, or has any information - "no matter how small to come forward".
The family is asking members of the public across the island of Ireland to share Mr Brennan's photo and appeal widely on social media to help raise awareness.
