A blast in Iran's Abadan's oil refinery killed one person and wounded 10 during a visit Tuesday by President Mahmoud Ahmadinejad, who was not affected and went on to make a televised speech, reports said.

"A technical fault led to an explosion in one of the units of this refinery," Fars news agency said, referring to the oil facility in the southwestern city of Abadan.

"The fire was immediately controlled ... The blast did not interrupt the president's programme," Fars added, giving a toll of six people injured and saying heavy smoke clouded the refinery and billowed across the city.

Mehr news agency said one person has been killed in the accident and another 10 wounded.

"Currently the control of the fire and the rescue operation has been completed and the investigation of the blast has commenced," Mehr said.

Ahmadinejad was at the refinery to inaugurate a unit that will elevate the nation's petrol production capacity by an extra 4.2 million litres a day.