The family of a Tyrone man last known to be at a Thai holiday resort have appealed for information about him.
Mr Conor Keightley's family have said they have not heard from him since before last weekend's disaster.
Mr Keightley, whose 31st birthday is today, had told a family friend in an e-mail that he was taking a boat trip on Christmas Day, but there has been no contact from him since. Another report, posted on a website established to gather information about the missing, said Mr Keightley was in Phi Phi on Christmas Day.
Speaking last night, his father Dermot said it was a difficult time for the Keightley family.
"He had gone out to Australia for a year and moved on to Thailand when his visa ran out around the beginning of November, and that's the last we heard of him," he told BBC Northern Ireland.
"He had been with a girl from Liverpool who is home now after her visa was up. We've been writing e-mails and other things, but we've come up with nothing."
Meanwhile, an historian from Co Antrim who was in Sri Lanka when the tsunami struck, has been in contact with his family.
Mr Alex Blair left an answering machine message for his neighbour in Ballymoney on Wednesday, but she only heard it yesterday. The message said he had been well away from the stricken coastal areas and was planning to return to Northern Ireland soon.
The public response to appeals for aid for disaster victims has reached unprecedented levels, according to Dean Houston McKelvey.
Known as Belfast's "Black Santa", he relaunched his annual Christmas charity appeal on the steps of St Anne's Cathedral on the city's Donegall Street when news of the disaster broke at the beginning of the week.
He has collected an additional £240,000 in just two days and vowed to continue the appeal for a further 10 days.
"The team at the cathedral are overwhelmed by the response. All day folk of all ages kept coming," he said.
"There are few communities in the world where people queue to donate to charities and today at times there were about 50 people in the queue." He cited the example of one woman who had come into the city to buy a new cooker in the sales.
"She decided to give the amount to the sit-out," he said. "Children of all ages emptied their home savings banks and gave their pocket money. One man whose mother's funeral had been held yesterday gave the money which she had in her purse." He added: "The demeanour of the people who came was like that of folk at the funeral of a friend and their grief at the disaster was expressed in charity."
In Co Down, the managing director of a Kilkeel-based aerospace firm is working to secure a plane to deliver aid to Thailand next week.
Mr Clifford McSpadden has asked for emergency supplies, especially sanitary items, for its Families for Families appeal.
"We felt there was something more we could do, and by bringing together business contacts, we were able to plug together little bits and pieces to make this project come alive."