Heraldo de Madrid - Iran's president visits site of port blast that killed 28

The blast occurred on Saturday at Shahid Rajaee Port in southern Iran, near the Strait of Hormuz, through which a fifth of world oil output passes.

With choking smoke and air pollution spreading throughout the area, all schools and offices in Bandar Abbas, the nearby capital of Hormozgan province, were ordered closed on Sunday to allow authorities to focus on the emergency effort, state TV said.

The health ministry urged residents to avoid going outside "until further notice" and to use protective masks.

Arriving in Bandar Abbas, President Masoud Pezeshkian expressed his appreciation to first responders, adding "we have come to see first-hand if there is anything or any issue that the government can follow up on".

"We will try to take care of the families who lost their loved ones, and we will definitely take care of the dear people who got injured," he said.

Pezeshkian had previously ordered an investigation into the cause of the blast.

Russia's embassy said Moscow was sending multiple "aircraft carrying specialists" to help fight the blaze. According to Russia's Ministry of Emergency Situations, one of the aircraft is a specialised firefighting plane.

The New York Times quoted a person with ties to Iran's Islamic Revolutionary Guard Corps, speaking on condition of anonymity to discuss security matters, as saying that what exploded was sodium perchlorate -- a major ingredient in solid fuel for missiles.

Defence ministry spokesman Reza Talaei-Nik later told state TV that "there has been no imported or exported cargo for military fuel or military use in the area".

The port's customs office said in a statement carried by state television that the explosion probably resulted from a fire that broke out at the hazardous and chemical materials storage depot.

- Area sealed off -

A regional emergency official said several containers had exploded.

Red Crescent chief Pirhossein Koolivand, in a video shared on the government's official website, gave an updated toll on Sunday of 28 people killed and more than 1,000 injured.

The ISNA news agency, citing the provincial judiciary, also put the number of dead at 28, with 1,242 injured.

Some of the injured were transferred for treatment in the capital Tehran -- more than 1,000 kilometres north -- Koolivand said.

Thick black smoke was still visible in live footage from the scene aired by state TV on Sunday.

"The fire is under control but still not out," a state TV correspondent reported from the scene.

The explosion was felt and heard about 50 kilometres away, Fars news agency reported.

Also at the scene on Sunday, Interior Minister Eskandar Momeni said "the situation has stabilised in the main areas" of the port, and workers had resumed loading containers and customs clearance.

Another official on site, Minister of Roads and Urban Development Farzaneh Sadegh, said only one zone of the port was impacted, and cargo "operations are still continuing as normal in the several other zones".

An image from Iran's Tasnim news agency on Sunday showed a helicopter flying through a sky blackened by smoke to drop water on the disaster-struck area.

Others showed firefighters working among toppled and blackened cargo containers, and carrying out the body of a victim.

The authorities have closed off the roads leading to the site, and footage from the area has been limited to Iranian media outlets.

- Mourning -

Beijing's foreign ministry said in a statement to AFP on Sunday that three Chinese victims were in a "stable" condition and that it had received no further reports of casualties.

The United Arab Emirates expressed "solidarity with Iran" over the explosion and Saudi Arabia sent condolences, as did Pakistan, India, Turkey and the United Nations as well as Russia.

The Tehran-backed Lebanese movement Hezbollah also offered condolences, saying Iran, with its "faith and solid will, can overcome this tragic accident".

Authorities declared a day of national mourning on Monday, and three days of mourning in Hormozgan province from Sunday.

The explosion ripped through the port as Iranian and US delegations were meeting in Oman for high-level talks on Tehran's nuclear programme, with both sides reporting progress afterwards.

While Iranian authorities so far appear to be treating the blast as an accident, it also comes against the backdrop of years of shadow war with regional foe Israel.

According to the Washington Post, Israel in 2020 launched a cyberattack targeting the Shahid Rajaee Port.

S.Llorente--HdM