A fire that badly damaged a wing of the former Our Lady's Hospital in Cork last night is being treated by gardaí as malicious.

The wing, which had been undergoing renovations into apartments, had been derelict for some time and there had been several reports of anti-social behaviour there in recent years.

Five units of the Cork City Fire Service responded to the emergency call, which they received shortly after 10pm.

The blaze caused extensive damage to the wing of the city's former mental hospital.

Two units of the fire service remained at the scene this morning dampening down what remained of the fire.

A Garda investigation is under way.