Situbondo, East Java. At least one person was killed and six others suffered severe burns and fractures after a house was destroyed in an explosion believed to have originated from firecracker-making materials on Wednesday, authorities said.

The blast, which occurred in Sumberanyar village, Situbondo regency, East Java, was described by residents as comparable to a large bomb detonation and was reportedly heard up to one kilometer away.

Police discovered materials used to manufacture firecrackers in the debris and are continuing their investigation into the cause of the explosion.

“The explosion was extremely loud, like a bomb, and could be heard within a radius of about one kilometer,” said Abdussalam, head of the local neighborhood association.

The fatality was identified as Supriyadi, 54, who was crushed by falling debris when the house collapsed. The injured victims — Kulsum, 60; Samsul, 22; Riko, 25; Abdur, 15; Fais, 20; and Fino, 15 — sustained serious burns or broken bones and were taken for medical treatment.

Police cordoned off the area over concerns that unexploded firecrackers might still be present. A bomb disposal unit was deployed to secure the site and neutralize any remaining explosive materials.

“Investigation at the scene must wait until the bomb squad declares the area completely safe,” Situbondo Police Chief Bayu Anuwar Siddiqie said at the scene.

Under Indonesian police regulations, the production of firecrackers containing more than 20 grams of gunpowder and measuring at least 2 inches (5 centimeters) requires official permits, including for storage, manufacturing, and distribution.

Unauthorized possession of explosive materials is also a violation of Indonesia’s 1951 emergency law.

Under the new Criminal Code that took effect this year, igniting firecrackers in a manner that endangers property or public safety carries a maximum prison sentence of nine years, or up to 15 years if it results in fatalities.