A powerful explosion Saturday in a former military barracks in southern Denmark killed at least two people, police said.

"We can confirm that two people have died. There could be more," police spokeswoman Helle Lundberg said, adding that the cause of the blast had not yet been determined.

"Our investigation into the cause of the explosion could take several days," she said.

Ulrit Mosekjaer, a local emergency services coordinator, expressed doubt that any munitions had remained in the barracks to cause the explosion.

"They were completely empty when they were sold to a private owner several years ago," he told AFP. "It must have been something else, but I don't know what."

Earlier, Lundberg said 174 families living within a 400-metre (435-yard) radius of the site in the small town of Andst had been evacuated because of the risk that there were dangerous fireworks inside the building.

"The police and fire brigade have evacuated the area because we know that there are big fireworks of the type used by professional pyrotechnicians inside the barracks," she said.

Danish news agency Ritzau, said six to eight buildings near the barracks had been damaged in the blast.