night may have been started deliberately.

Fire crews were called to the Number 1 Club, at the east end of the hospital just after 6.30 p.m.

It is understood a small fire damaged a section of floor before firefighters put it out.

A thick dark smoke was produced from burning plastic, but what caused the plastic to burn is under investigation.

A spokesman for the Fire Service declined to speculate on the cause of the blaze -- but added arson had not been ruled out.