A fifth person has been arrested by police investigating a petrol bomb attack in Derry city that left a man critically ill in hospital.

Thomas Curry, 46, is being treated at the Royal Victoria Hospital in Belfast after he was set on fire at his home.

Two men smashed a window of his house and then fired the petrol bomb inside where he was sitting on a settee.

Police said they are treating the attack as attempted murder.

Mr Curry, who lived alone was dragged from the flames by neighbours at Ben Varden Avenue.

The 20-year-old was arrested in connection with the incident earlier today.

Two other men - aged 24 and 25 - and a 45-year-old woman are already in custody.