Six people, including a nine-year-old boy, have been rescued after a boat sank off the coast of County Donegal in the Republic of Ireland.

The half deck trawler, the Charlies Angels, started to take in water after developing engine problems at about 1900 BST on Saturday on Lough Swilly near Buncrana.

The alarm was raised by a 999 distress call from a mobile phone on board the boat.

A police water unit was patrolling nearby but by the time it arrived at the scene the boat had sunk.

The Garda boat crew could see the bow of the stricken vessel disappearing under the surface of the sea

Liam McGee Lough Swilly Lifeboat

All six had been in the water for about 20 minutes before being brought to safety by the Garda unit.

An Aer Corps rescue helicopter later airlifted the boy - who suffered a gash to the side of his head - and one woman and two men to hospital in Letterkenny.

The remaining two men were taken to hospital by road.

All six people were discharged after being treated for shock and hypothermia.

Liam McGee, a member of Lough Swilly Lifeboat, said they had a narrow escape.

"The boat had just gone down," he said.

"The Garda boat crew could see the bow of the stricken vessel disappearing under the surface of the sea, so the people in the boat had just been in the water for several minutes.

"They were very lucky indeed.

"One would hate to think but fatalities could well have occurred."

An investigation is under way to find out what caused the boat to sink.