Saboteurs attacked a pipeline carrying natural gas from Iran to Turkey in Turkey's eastern province of Agri late on Monday, halting the flow, Turkish Energy Minister Taner Yildiz and state gas company Botas said.
There was no immediate claim of responsibility, but the attack bore the hallmark of the Kurdistan Workers Party (PKK), whose camps in northern Iraq have been bombed by the Turkish air force in recent days and which has struck the pipeline before.
"An explosion occurred as a result of a sabotage about 15 kilometers inside the Turkish border on the Turkey-Iran gas pipeline," Yildiz said in a statement.
The blast caused a fire which was swiftly put out, he said.
The pipeline, which carries around 10 billion cubic meters of Iranian gas to Turkey annually, frequently came under attack by Kurdish militants during the 1990s and up until 2013, when a ceasefire was established.
A Botas official said repairs were underway but it was not clear when the gas flow would resume.
Turkey buys around a quarter of its 40 billion cubic meters of piped natural gas imports from Iran, making its eastern neighbor its second biggest supplier after Russia. Natural gas is used for almost half of Turkey's electricity generation.