BOTAS said a gas leak was believed to be the cause of the blast and teams were on their way to repair the pipeline.
"Repair and maintenance work will be completed in the shortest time possible and the purchase of gas from Iran will resume," it said.
The Turkey-Iran natural gas pipeline, which runs from the northwestern Iranian city of Tabriz to Ankara, began pumping in December 2001, two years behind schedule because of construction delays on the Turkish side and subsequent wrangling between the two sides over technical matters.
The agreement, signed in August 1996 by Turkey's Islamist then Prime Minister Necmettin Erbakan, has been criticized by the United States on grounds that it rivals a major project to carry natural gas from Turkmenistan to western markets via Turkey.
Under the 25-year deal, Turkey was scheduled to import four billion cubic meters (140 billion cubic feet) of gas from Iran in 2002, with the amount projected to reach 10 billion cubic meters (350 billion cubic feet) in 2007.