Police are treating the incident as arson and have carried out door-to-door enquiries.

    The householder’s father said his son had behavioural problems but had done nothing to warrant such an attack.

    “He hasn’t committed murder or stolen anyone’s car,” he said.

    The house had been empty at the time and no one seemed to have noticed anything until 11am, he said.

    “It’s only lucky there were two fire doors and they were closed and that contained it to the living room.”

    The man said he believed it was the second time his son’s house had been targeted. A fire late last year was put down to an electrical fault, he said.

    “Somebody must have seen something. If they get away with this, we need to stop them coming back - there could be loss of life or serious injury,” he said.

    The man said he had contacted the Housing Executive and told them his son was on benefits, but they were only prepared to do so much.

    “They expect us to foot the bill for repairs,” he said.

    “They are not prepared to do anything unless the house is completely burned to the ground.”

    He said Housing Executive staff had told him the culprits would probably prove to be on benefits as well and it was unlikely the costs could be recouped from them.

    “The interior has got to be redecorated at my expense. We are cleaning it up ourselves - the expense of that lies down to us,” he said.

    The man said his son had only moved back to the house less than a fortnight ago after clearing up the damage caused by the previous fire.

    On the Friday following the arson attack, the family discovered that a window had been broken in the front door in a separate incident.

    The father urged anyone with information to contact the police. Detectives in Enniskillen are investigating the incident and can be contacted at 028 6632 2823.

    A Housing Executive spokesman said the tenant was no longer living in the property and its local branch had arranged for the house to be secured to protect it and neighbouring properties.

    “The tenants should claim against their home contents insurance for any damage that was caused to the interior furnishings of the property,” she said.