A massive explosion was reported at the Shahid Rajaee Port in southern Iran, local media reported on Saturday, leaving four people dead and over 500 injured.

“Unfortunately, at least four deaths have been confirmed by rescuers,” the head of the Red Crescent Society’s Relief and Rescue Organisation, Babak Mahmoudi, told state TV.

State television, citing emergency services, reported that “516 people have been injured as hundreds have been transferred to nearby medical centres” in the southern province of Hormozgan, where the Shahid Rajaee port is located.

The explosion was reported at around 12:30am local time (2100GMT/2am PKT) on Saturday.

The strategically important port, located in the southern Hormozgan province, lies around 15 kilometres southwest of the port of Bandar Abbas on the northern shore of the Strait of Hormuz.

The explosion was likely caused by poorly stored chemical materials detonating, according to Hossein Zafari, a spokesperson for Iran’s crisis management organisation.

“The cause of the explosion was the chemicals inside the containers,” he told Iran’s ILNA news agency. “Previously, the Director General of Crisis Management had given warnings to this port during their visits and had pointed out the possibility of danger.”

The explosion occurred as Iran began a third round of nuclear talks with the United States in Oman, but there was no immediate indication of a link between the two events.

According to the semi-official Tasnim News Agency, it could have been caused by the explosion of a fuel tank, however, there has been no official statement on it so far.

The report said rapid response teams were immediately dispatched to the site of the incident, with port operations suspended temporarily to allow security and emergency forces to restore order.

The semi-official Fars News Agency quoted local officials in Hormozgan as saying the explosion occurred at a section of the Shahid Rajaee Port dock, adding that efforts are underway to extinguish the fire.