Vladimir Putin was one of the first world leaders to help Iran and sent several emergency planes to the region after a massive explosion at a critical port near the Strait of Hormuz.

The fire still exploded nearly 24 hours after the explosion of the huge Shahid Rajay port in southern Iran, the most important port and major artery of the world trade in the United States. The number of deaths has increased to at least 28, and the number of injured has increased to more than 1,000.

Iranian President Masoud Pezeshkian flew to Bandar Abbas, a city of 20 miles from the port of Hormozgan Province, and briefed the investigation and rescue operations.

Bandar Abbaswere's schools and offices ordered the closure Sunday as smoke and air pollution spread across the area, state television reported. The Ministry of Health urges residents to avoid going out until further notice and use protective masks.

Early signs suggest that the explosion appeared to be an accident rather than a intentional attack. The Tehran prosecutor's office said it has filed lawsuits against a variety of politically persuasive media, reflecting officials' concerns about speculation that the explosion was a terrifying act or due to military errors.

CCTV footage circulating on Iranian media showed that a local fire began to appear in a container at five minutes noon, and then quickly spread to other containers, and port workers began to escape. Then a huge explosion occurred within two minutes, knocking on the camera.

The Ministry of the Interior initiated an investigation. There is no official explanation for the explosion, but more and more reports say that the storage of chemicals in containers at high temperatures may be blamed.

Evidence of smaller previous events was mentioned and claims that most regimes surrounding health and safety programs, especially inspections on chemical storage, were signed.

The Kremlin website said Putin had communicated his “true words of sympathy and support for the victim’s family and his desire to restore all the injured.” Russia dispatched planes carrying expert firefighters.

The explosion occurred at the beginning of the third round of negotiations between the United States and Iran, aiming to lead to new controls on Iran's nuclear program in exchange for lifting U.S. sanctions.

The Iranian Foreign Ministry described the negotiations mediated by Oman and held in Muscat, which were more serious, practical and detailed than previous negotiations. Another round of negotiations will take place within a week.