A 15-year-old north Queensland boy has undergone emergency surgery after a homemade bomb exploded on Sunday afternoon.

Mackay Police say two boys, aged 14 and 15, were experimenting with low-level explosive materials when one of the bombs went off.

The 15-year-old suffered horrific blast injuries, losing a hand and suffering facial, chest and throat injuries.

Surgeons were trying to rebuild the boy's hand on Sunday night.

Police say the boys made the devices from "items used for parties".

"What they were doing was wrapping up some low-level explosive material into insulation tape with a view to throwing it onto the ground and creating that explosion," said Mackay Police Inspector Andy Graham.

"Even though it is low-level stuff and readily available around the household, [it] can have catastrophic results."

Police say there were no parents at home when the explosion occurred around 3:00pm.

"One of the children was out of the room at the time of the explosion," Inspector Graham said.

The 15-year-old is in a stable condition at Mackay Hospital.