At least one person was killed and 14 were injured in an explosion in the southern Iranian port of Bandar Abbas on Saturday, according to the Iranian news agency Tasnim.

The blast hit an eight-story residential building, with state television reporting that the blast destroyed "two floors, several vehicles, and shops" in the area of Moallem Boulevard in the city. 

The ‍semi-official Mehr ​news ​agency, citing the local fire department chief, said that the explosion at the building in the port city in the Persian Gulf was caused by a gas leak.

Earlier, Iran's official IRNA news agency quoted the crisis management director for Hormozgan province, Mehrdad Hassanzadeh, as saying the investigation into the cause of the explosion was ongoing.

What do we know about the explosion?

Following online rumors, the Islamic Revolutionary Guard Corps (IRGC) said none of the buildings belonging to its naval forces in the province were targeted, according to a statement carried by the Fars news agency.

Separately, state-run Tehran Times reported that a gas explosion ‌in the ⁠city of Ahvaz near the Iraqi border left four people dead. Two Israeli officials told Reuters that Israel was not involved in Saturday's ‍blasts.

The blast occurred one day before Iran's planned naval drill in the Strait of Hormuz, the narrow entrance to the Persian Gulf through which one-fifth of the world's oil supply passes. The US military had warned Iran against threatening its warships or commercial traffic in the strait, through which the Iranian port city of Bandar Abbas sits.

The incidents came at a sensitive moment in relations between Washington and Tehran, after the US sent an aircraft carrier group into the area.

On Wednesday, President Donald Trump again issued threats against Iran, calling on Tehran to come to an agreement on its nuclear program.

Iran says 'framework for negotiations' with US underway

Meanwhile, a top Iranian security official said that work on a framework for negotiations with Washington was progressing.

"Contrary ​to the ​atmosphere being created by artificial media warfare, the formation ‍of a structure for negotiations ​is underway," Ali ⁠Larijani, head of Iran's Supreme National Security Council, wrote on X. ⁠He did not give further details.

Earlier, Iranian army chief Amir Hatami warned the US and Israel against any attacks, saying his forces were "at full defensive and military readiness" to respond. 

He said any "mistake" would endanger the "enemy('s)" own security, stressing that Iran's nuclear technology and expertise "cannot be eliminated."

Edited by: Saim Dušan Inayatullah, Dmytro Hubenko