BERLIN - At least 13 people were injured when a yacht exploded in northern Germany late Tuesday, German news agency dpa reported early Wednesday, citing police sources.

Most of the injured are firemen, as they had been called to put out a fire on the yacht in the north German port town of Minden, according to a police spokesman.

"Six of them suffered serious injuries. One of them is critical," the spokesman was quoted as saying.

The blast blew the yacht several meters into the air and completely destroyed a car parked nearby. Two other boats were also damaged in the powerful explosion.

The cause of the incident was unclear. Police suspect it was triggered by an explosion of the boat's battery.

The damage was estimated at about 500,000 euros ($574,000), said the spokesman.