A suspected World War II shell exploded beneath a stilt house in Indonesia’s Papua region, killing five people and injuring nearly 20 others.

The powerful blast destroyed nine homes, sent flames and smoke into the air, and left three people missing.

Police believe the explosion was caused by an old bomb or mortar left over from World War II, though investigations are ongoing.

Authorities are continuing rescue and identification efforts as some human remains have not yet been identified, CBS News has reported.

The incident highlights the continuing danger of unexploded wartime munitions, which have caused deadly explosions in several countries in recent years.