Indonesian fire fighters tackle a blaze triggered by the blast in Semarang city (Photo: VNA)

 The warehouse is in the Mobile Police Brigade headquarters in Srondol, close to the city of Semarang in Indonesia’s Central Java province.

The explosion happened at 7am (local time), provincial police chief A Dahniel said, adding that the explosives stored in the warehouse had been found by residents.

The cause of the blast has been investigated and fire fighters had been deployed to tackle a blaze that it triggered./.