Twenty-nine people, including unborn twins, died in the bombing

The film, Omagh, has been selected for official competition at the San Sebastian Film Festival in Spain.

The drama is one of just 15 titles worldwide to be shortlisted for the festival's Golden Shell prize.

It examines the horrific events and appalling aftermath of the bombing, which killed 29 people and unborn twins in the County Tyrone town in August 1998.

Based on first-hand research, and in consultation with the Omagh Support and Self Help Group, the drama looks at the search for the perpetrators of the bombing and the persistent struggle of the families who are still demanding answers.

The film is seen very much from the perspective of Michael Gallagher, whose son Aidan, 21, was killed in the bombing.

'Greatest tragedy'

He said the recognition was "absolutely fantastic" and the crew had done an extraordinary job.

"I am over the moon that the film is making its mark and I'm pleased that people across the world will have the opportunity to see how we dealt with the greatest tragedy of our lives," he said.

The film was jointly written by Guy Hibbert and Paul Greengrass, who were behind an award-winning film about the 1972 Bloody Sunday killings.

Directed by Pete Travis and produced by Ed Guiney, along with Mr Greengrass, the film was made from the victims' point of view.

The Omagh bombing was the worst single atrocity in NI

Mr Guiney said he was delighted to have been recognised by one of the premier festivals of the Autumn season.

"San Sebastian is in the Basque region so it is even more relevant as local people will understand the context of the film," he said.

"It is great to be coming from one country to be screened in another which has so recently suffered bereavement.

"Our plan with the film was always to get it out to an international audience. It's such a powerful story which people in Ireland already know too well."

The production shows many of the victims, including the children who died, arriving in the town in the moments before the blast.

The cast was drawn from all parts of Ireland, north and south of the border, and includes Academy Award winner Brenda Fricker and Omagh-based actor Gerard McSorley.

The Hell's Kitchen International/Tiger Aspect production was co-financed by the UK's Channel Four, Irish national broadcaster RTE and Bord Scannan na hEireann/the Irish Film Board (BSE/IFB).

The Donostia-San Sebastian International Film Festival will take place from 16-25 August.