Authorities say seven people are still missing after deadly explosions at a facility storing pyrotechnic material.

Two explosions at a military facility in the Bolivian city of Viacha have killed at least 10 people and injured dozens of others, authorities said.

The blasts occurred on Friday in an area used to store pyrotechnic material, about 30km (18 miles) from the administrative capital, La Paz, Bolivia’s Ministry of Defence said.

Viacha health director Rita Nebraska told a local television station that between 10 and 15 people were believed to have been killed and 62 others were injured.

She said 14 of the wounded were transferred to hospitals in La Paz, including a girl with third-degree burns.

Fireworks were stored at the military facility, but the cause of the explosions remains under investigation, police spokesman Roger Roca said. He added that seven people were still missing.

Firefighters warned that a heat source remained at the site, Nebraska said, urging residents to stay at least 150 metres away because of the risk of another explosion.

Police said dozens of nearby homes were damaged and that many civilians were injured by shattered glass.

About 50 civilians and six military personnel injured in the explosions “have been treated … by the different medical centres of Viacha”, Deputy Minister of Defence Ernesto Justiniano Urenda said in a statement.

An investigation is under way to determine the cause of the explosions, how the pyrotechnic material was stored and whether anyone was responsible, he added.

Footage posted on social media showed one of the explosions shattering windows in nearby buildings and sending debris into the air as thick black smoke rose from the facility.