A MOBILE phone charger is believed to have sparked a fire in a Gracemere unit block in the early hours of yesterday morning.

A QFES spokesperson said multiple 000 calls were received reporting the fire at a Lawrie St address.

"We had reports of a fire in a bedroom in a unit block," the spokesperson said.

"We sent three crews out, one from Gracemere and two from Rockhampton, and the Gracemere crew arrived within 10 minutes.

"When the Gracemere crew arrived, smoke and fire was visible. All occupants were out of the house."

The spokesperson could not confirm the fire was started by a phone charger but neighbours believed the fire was caused by a phone charger that was plugged into an extension cord.

QFES is still investigating the cause of the fire, which caused extensive internal damage to the unit.

Fire8 Queensland director Steve Ward said the dangers of leaving appliance chargers switched on was a main focus of Fire8 fire safety courses.

"In our courses we certainly advise people that when they finish using a phone charger or any kind of charger to switch it off," Mr Ward said.

"There is the real possibility it could overheat.

"You could leave it switched on for 100 years and nothing will happen, but one day something might just happen."

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