A fire alarm last night forced the evacuation of more that 3500 fans just three minutes before headline act silverchair was due to hit the stage.

The concert crowd was evacuated from the Townsville Entertainment Centre and Convention Centre after alarms went off at about 9:12 pm.

Disgruntled fans booed outside the centre, as two Queensland Fire and Rescue Authority trucks arrived at the scene.

Acting station officer Brian Corrigan said a manual call had been activated by the smashing of the alarm glass. "It was just a false alarm," Mr Corrigan said.

He believed that an individual broke the glass, but whether or not it was a deliberate act or an accident remained to be seen.

"Someone could have accidentally leant upon it or dropped something on it, we would like to think it was an accident rather than a mischevious act," he said.

After an investigation, the alarms were stopped, and about six minutes later fans were allowed back into the centre. About 15 minutes later, silverchair - fronted by Daniel Johns - hit the stage to the cheers of the crowd.

Skinflint, Jebediah and Grinspoon were the support acts.