TEHRAN: An explosion blamed on a gas leak rocked Iran's largest refinery Tuesday around the time of a visit to the plant by President Mahmoud Ahmadinejad. Iranian media reported that up to two people were killed. The blast occurred just before Ahmadinejad was to inaugurate and expansion project at the 400,000 barrel per day refinery in the southwestern city of Abadan, and injured 20 people, the semi-official Fars news agency said. The explosion was blamed on a “gas leakage,” but no other details were provided. Ahmadinejad himself was not injured. Conflicting reports over the toll and timing of the blast surfaced but officials at the plant were not reachable for comment. The semi-official Mehr news agency said two people were killed in the explosion that took place while the president was visiting. Mehr said Ahmadinejad ordered a special plane to airlift those critically injured to Tehran. Meanwhile, state television said the explosion occurred after Ahmadinejad had left the site and the station broadcast a live feed showing the president speaking to officials at a local hall in Abadan. The plant alone accounts for about 25 percent of Iran's fuel production, which is about 1.67 million barrel per day. Fazel Kaebi, an Abadan resident, told The Associated Press over the phone that he saw ambulances and rescue teams rush to the site shortly after the explosion. He said the townspeople had noticed black smoke coming from the refinery in the past few days, which he speculated could have been from a fire. Firefighters quickly extinguished the blaze, the reports said, but the extend of the damage was not immediately clear.