I hope (people) will make up their own mind about what happened

Michael McKinney, Bloody Sunday Trust

Afterwards Mr McGuinness, who is due to testify to the ongoing Saville Inquiry into the events of that day, described the dramatisation as "powerful and emotional".

He also embraced the actor James Nesbitt, an Ulster Protestant who starred in the production.

Mr McGuinness praised producer Mark Redhead and writer-director Paul Greengrass for tackling such a traumatic event in which 13 civilians were shot dead by British paratroopers after a civil rights march in the city.

"I think the fact that English people are prepared to tackle a subject that is of such great embarrassment to the British Government is to their eternal credit and I think helps the peace process," he said.

'Tough'

Mr McGuinness said Bloody Sunday had left a deep scar on the city.

"What really touched me watching the film was seeing the people of Derry," he said.

Martin McGuinness: Film is good for peace process

"They were allowed to participate and make their own film and tell the world the truth of what happened."

Nesbitt, who was just six-years-old on Bloody Sunday, spoke to relatives after the screening.

He said he had been extremely moved by the film and the audience reaction.

"These people have lived with it for 30 years. I only lived with it for a year," he said.

"If it was tough for me, it's a damn sight tougher for them."

Television screening

The former Bishop of Derry Edward Daly, who was a young priest on Bloody Sunday, said the film had provided a powerful anti-war statement.

"I found it a deeply emotional experience. The memories of that day live with me all the time.

Actor James Nesbitt met relatives of the victims

"This film once again underlines that dialogue is always preferable to armed conflict," he said.

Michael McKinney, of the Bloody Sunday Trust, whose brother William was one of the victims, said he hoped millions of people in Britain would watch the film when it is broadcast on ITV on 20 January.

"I hope they will make up their own mind about what happened," he said.

"We always said that our people were all totally innocent of the allegations made against them by the lawyers, the army and the British Government."

The film will be premiered at the prestigious Sundance Festival in Utah on 15 January.

The John Sheridan production received a grant of �287,500 from the Film Council last year, prompting controversy because of the film's subject matter.