Police are treating a fire at a nightclub in Londonderry as arson.
The blaze broke out at Envy Nightclub on the Strand Road shortly before 7pm on Thursday.
A number of nearby premises were evacuated, roads were closed and residents were advised to keep their windows shut for a time.
The Fire Service said at the height of the incident there were six fire appliances and 50 firefighters involved in efforts to tackle the fire.
They said it was dealt with by 1.13am on Friday.
"The NIFRS has ruled this to be deliberate ignition, and so we are treating this as arson," a spokesperson added.
“The investigation is still at an early stage and we have no motive for the attack and we are keeping an open mind."