Iran's supreme leader Ayatollah Ali Khamenei ordered a thorough investigation Sunday into the causes of a major blast at a key southern port that killed at least 40 people and injured more than 1,000.

His instructions came after President Masoud Pezeshkian visited the blast scene in Shahid Rajaee Port near the strategic Strait of Hormuz where a fire still blazed on Sunday more than 24 hours after the explosion.

"Security and judicial officials are obliged to thoroughly investigate, uncover any negligence or intent, and follow up in accordance with regulations," Khamenei said in a message carried by state television.

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 to allow authorities to focus on the emergency effort, state television said.

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

Arriving in Bandar Abbas, the president 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........

© Al Monitor