No one was injured when a wooden gazebo within the Funky Monkey on Manoel Island caught fire on Wednesday evening, the police said.
The fire was brought under control after the Civil Protection Department rushed to the site in Gżira at around 7.45pm.
Arson has not been ruled out.
Meanwhile, Facebook users reportedly saw a group of hooded teenagers running away from the music venue and soon after a plume of smoke was spotted over the establishment.
A rubbish fire was also reported in Luqa at around the same time.