The blast in Indonesia's restive eastern region of Papua startled residents with a loud explosion on Sunday afternoon, sending up a ball of flames followed by a thick column of smoke, according to footage aired by Kompas TV.

Nine homes were destroyed.

"The source of the explosion is strongly suspected to have been a bomb or mortar left over from World War II," Papua police spokesman Cahyo Sukarnito said.

Three people are still recorded as missing, but Cahyo said several body parts have yet to be identified.

At least 19 people were treated for minor injuries, he added.

"We will provide further updates once the search for victims and the investigation have been completed," said Cahyo.

Last year, nine civilians were among 13 people killed in West Java province when an explosion occurred as Indonesian troops attempted to dispose of rejected munitions by detonating them in a pit.

Indonesia was a major battle zone during WWII when Japanese forces occupied what was then the Dutch East Indies, and Allied forces fought to retake control.