At least 25 people have died and 800 others were injured in a large explosion at the Shahid Rajaee port near Bandar Abbas in southern Iran on Saturday.

State media offered the casualty figures, saying authorities identified only 10 of the dead, including two women.

It also reported the fire was under control and will be fully extinguished later Sunday. It also said activities have resumed at the port, showing footage of containers of a commercial ship being unloaded.

The explosion affected offices belonging to the port, and its intensity was sufficient to cause tremors felt in nearby cities, according to domestic reports. The blast also shattered the glass of buildings several kilometres away from the site of the incident

State television also reported that there had been a building collapse caused by the explosion, though no further details were offered.

Local authorities warned about air pollution from chemicals such as ammonia, sulfur dioxide and nitrogen dioxide. As a precaution, schools in Bandar Abbas will remain closed on Sunday.

The blast at the port comes as Iran and the United States met in Oman on Saturday for a third round of negotiations over Tehran’s rapidly advancing nuclear programme

?What caused the explosion

The director general of crisis management in Hormozgan province, which includes Bandar Abbas, stated that the cause of the explosion remains unknown.

The Customs Administration of Iran blamed a “stockpile of hazardous goods and chemical materials stored in the port area” for the blast, the state-run IRNA news agency said on Saturday.

Private security firm Ambrey reported that the port took a shipment of “sodium perchlorate rocket fuel,” in March, which was going to be used to replenish Iran’s missile stocks.

“The fire was reportedly the result of improper handling of a shipment of solid fuel intended for use in Iranian ballistic missiles,” the firm said

Iranian officials have not acknowledged taking the shipment.

No one in Iran outright suggested that the explosion came from an attack. However, even Iranian Foreign Minister Abbas Araghchi, who led the talks, on Wednesday acknowledged that “our security services are on high alert given past instances of attempted sabotage and assassination operations designed to provoke a legitimate response.”

Social media videos showed reddish-hued smoke rise from the fire before the detonation, suggesting a chemical compound may have been involved in the blast, similar to the blast in Beirut in 2020. Black billowing smoke filled the sky following the blast. Others videos showed glass blown out of buildings kilometres away from the epicentre of the explosion.

Meanwhile, state media footage showed the injured crowding into at least one hospital, with ambulances arriving as medics rushed one person by on a stretcher.

The Shahid Rajaee port is a major facility for container shipments for the Islamic Republic that handles some 72.5 million metric tonnes of goods a year.

The Interior Ministry said that it launched an investigation into the blast. Iranian President Masoud Pezeshkian also offered his condolences for those affected.