A man has gone on trial accused of the manslaughter of Co Monaghan teenager Jason McGovern, who died after he was attacked in Omagh, Co Tyrone on New Year's Eve 2012.

Mr McGovern, from Tydavnet, was found dead in a friend's house on 1 January 2013 after the assault outside a nightclub in Omagh.

Mark Donnelly, 22, from Greencastle Road in Omagh, denies manslaughter and affray.

The prosecution alleges that after Mr McGovern left a bar with a friend to get a taxi home they were subjected to an unprovoked assault by a group of young men.

Mr McGovern was then attacked a second time and fell and hit his head on the ground.

He returned his friend's house in Mullan, Co Monaghan, where he was found dead around midday.

He died as a result of bleeding to the brain caused by a fractured skull.

When arrested and charged, Mr Donnelly told police he was definitely not guilty.

The prosecution case is that while Mr Donnelly did not intend to kill he had been responsible for Mr McGovern's death.

The trial at Dungannon Courthouse is expected to last up to two weeks.