A fire on an oil platform in Iran’s Rag-e-Sefid oilfield killed four people and destroyed the Fatah 95 drilling rig, Iranian media reports, according to KUNA.

The fire has been blamed on a leakage of combustible materials, Xinhua Net reports.

Rag-e-Sefid is located in Bushehr in southwestern Iran. The oilfield produces 180,000 barrels of crude per day, according to KUNA.

Last week a fire killed six at a refinery in Tehran, Reuters reported at the time. Since then, a seventh individual has died from injuries caused by the fire, according to Tasnim News Agency.

Iran’s oil and gas network has suffered from years of sanctions against the industry, ABC News reports. Despite the aging infrastructure, the government has been ramping up production after the ending of international sanctions.

In June, a fire at Iran’s Isfahan refinery injured 10 workers. According to the refinery spokesman, operations remained unaffected, Reuters reported at the time.