'Blast' at new Iran oil refinery as Ahmadinejad visits
At least one person has been killed and 20 injured in a blast at an Iranian refinery around the time of a visit by Iran's president, local media say.
A technical problem caused the blast and then a fire, Fars news agency said.
Thick smoke was seen rising from the refinery but the fire was under control, the semi-official agency said.
President Mahmoud Ahmadinejad was not injured, and made a televised speech to mark the opening of the oil refinery in the south-western city of Abadan.
A senior Iranian official said the incident was "not an act of intentional sabotage".
"Experts had forewarned that Abadan refinery was not ready to be inaugurated," Hamid-Reza Katouzian, head of Iran's parliamentary energy committee, was quoted as saying by Reuters news agency.
"The incident in Abadan refinery was due to technical problems."
Another news agency, Mehr, said the explosion was caused by a gas leak and some employees inhaled toxic substances.
It reported that at least two people had been killed.
There were conflicting reports about whether the blast had occurred before, during or after Mr Ahmadinejad's visit.
In August last year, Iranian authorities denied that an explosive device had been thrown at Mr Ahmadinejad's convoy near the city of Hamedan.
Analysts say Mr Ahmadinejad is currently involved in a power struggle with Supreme Leader Ayatollah Ali Khamenei, after the latter reinstated the intelligence minister the president tried to sack.
The refinery is being launched in two phases and ultimately will produce more than 6m litres (1.3m UK gallons) of petrol a day, mostly for domestic consumption.
Correspondents say Mr Ahmadinejad's presence shows the importance Iran, a major oil producer, places on increasing its refining capacity as sanctions hit its ability to import petrol.
Accidents are relatively frequent in Iran's oil and gas infrastructure, and state media said similar incidents had been reported at the plant in the weeks before it opened.
There have also been media reports of two acts of sabotage against the main gas pipeline from the south to the capital Tehran, though they said supply was not affected.
The port of Abadan has a special significance in Iranian history after post-war Prime Minister Mohammad Mossadeq nationalised the Iranian assets of the Anglo-Iranian oil company.
His move led eventually to a CIA-backed coup which overthrew him and led to decades of Iranian animosity towards the West.