By Deutsche Presse-Agentur
The blast occurred Monday evening in a chemical storeroom at the Dak Lak Provincial Police Department, said the department's director Major General Tran Ky Roi.
The storeroom was being used to store explosive materials seized from suspects, Roi said.
Another officer in Dak Lak stressed that foul play was not suspected.
"This was an unfortunate accident, not a terror attack," Senior Lieutenant Colonel Bui Trong Tuan said at a press conference Tuesday morning.
The explosion lasted approximately 10 seconds and could be heard as far as half a kilometre away.
Nearby houses were damaged by the debris, which was propelled dozens of metres, officials said.
Police cordoned off the site and were investigating the cause.