Five people have been killed in two separate explosions in Iran which local officials and state media say were caused by gas leaks.

One person was killed and 14 injured in a blast at a residential building in the southern city of Bandar Abbas on the Gulf coast, a local official told Iran's semi-official Mehr news agency.

Another explosion killed four people in the south-western city of Ahvaz, the state-run Tehran Times reported.

It comes as tensions persist in the region after a build-up of US forces in the Gulf and pressure on Tehran from US President Donald Trump to strike a deal on its nuclear programme.

Trump was asked by journalists whether he had decided what to do in Iran while travelling to Florida on Saturday night and said: "I certainly can't tell you that."

But he added, reiterating comments made to Fox News earlier in the day, that Iran was talking "seriously" to Washington.

He said he hoped they would negotiate something acceptable, and noted that the US had "very big powerful ships" in the region.

Earlier, in the port city of Bandar Abbas, state TV said an explosion had ripped though an eight-storey building, "destroying two floors, several vehicles, and shops" in the Moallem Boulevard area.

The local fire department chief Mohammad Amin Liaqat said a preliminary assessment showed it had been caused by a gas leak and "build-up".

"My colleagues will give more details in the next few hours," he said in a video published by Mehr.

Mehrdad Hassanzadeh, a regional official, told the news agency that the injured had been taken to hospital.

Semi-official news agency Tasnim denied social media reports that a Revolutionary Guards Corps navy commander had been targeted in the blast.

Elsewhere, the Tehran Times reported a second explosion at a residential building in the Kianshahr neighbourhood of Ahvaz, near the border with Iraq.

It reported that emergency officials had rescued a child trapped beneath debris and transferred him for medical treatment.

Trump told Fox News on Saturday that Iran was "negotiating", adding that Washington could not share its plans with its allies in the Gulf.

"We'll see if we can do something, otherwise we'll see what happens... we have a big fleet heading out there."

Iran's President Masoud Pezeshkian said conflict would not be in the interest of either country, nor the broader region.

"The Islamic Republic of Iran has never sought and in no way seeks war," he said during a call with his Egyptian counterpart Abdel Fattah al-Sisi, news agency AFP reported, citing a statement from Iran's presidency.

Separately, the head of the country's Supreme National Security Council Ali Larijani met the Qatari prime minister in Tehran on Saturday and "reviewed ongoing efforts to de-escalate tensions in the region", Qatar's foreign ministry said.

Larijani, whom the Kremlin said had also met Russia's President Vladimir Putin for talks on Friday, wrote on X: "Contrary to the hype of the contrived media war, structural arrangements for negotiations are progressing."

Iran's foreign minister has said Tehran was open to talks with the US provided they were based on trust and respect, but cautioned that its missile defence system would "never" be the subject of negotiation.

Trump told Tehran on Wednesday that time was "running out" for it to reach a deal on its nuclear programme - which Iran insists is peaceful - and later said they must also "stop killing protesters" to avoid military action.

It came after he promised to intervene to help protesters who had been subject to a brutal crackdown in the country earlier this month, though he later said he had heard on good authority that the execution of demonstrators had stopped.

The US-based Human Rights Activists News Agency says it has confirmed the killing of more than 6,300 people since the unrest began in late December, and was investigating another 17,000 reported deaths.