The blast happened yesterday as a team of police, coast guard, marine and fire personnel disposed of firecrackers retrieved from a nearby warehouse, where an explosion on June 29 killed five people and injured 38 others, in Zamboanga city on Mindanao island.

The fireworks were the third and final batch to be taken from the warehouse to an abandoned government-owned shooting range for a controlled explosion, regional police spokesman lieutenant colonel Helen Galvez told AFP by telephone.

They had been offloaded from a pick-up truck and were being doused with water when they ignited prematurely.

“It was accidental,” Galvez said.

“It was not intended to be a massive explosion.”

Twenty members of the disposal team were injured, including six seriously.

Seven civilians suffered minor injuries when the blast damaged a dozen houses and other buildings nearby, as well as four vehicles.