Four people were killed and 6 were injured this morning after a box of ammunition exploded during handling near an ordnance depot in Maharashtra Wardha. Four were killed on the spot, and two died during treatment at a hospital, the police said. The ammunition exploded while it was being unloaded for disposal, a defence official said. Around 10 15 labourers were on the demolition ground near the Central Ammunition Depot, senior police officer Nikhil Pingle said.