The blast, which also wounded several soldiers, occurred Saturday afternoon at the army base in Kampong Speu province, Hun Manet said in a statement on Facebook, without giving more details.

"I am deeply shocked to receive the news of the ammunition explosion incident," Hun Manet said, expressing his "deepest condolences" to the families of those killed.

It was not immediately clear what had caused the explosion.

Pictures on social media showed a destroyed one-storey building wreathed in smoke, with residents of a nearby village also sharing images online of broken windows.

In the statement, Hun Manet said he had ordered the Minister of National Defense and the Commander-in-Chief of Royal Cambodian armed forces to urgently arrange funerals for the soldiers who died.