TEHRAN (Reuters) - Iranian security forces killed three people on Monday and arrested four others they suspected of being behind a pipeline blast which halted gas exports to Turkey last week, Iran's student news agency ISNA reported.
Officials in Maku, a city in Iran's West Azerbaijan province, said the militants had crossed the border from Iraq to blow up the pipeline and that at least one was a Turkish citizen.
"'Jamil', a Turkish national and head of this terrorist group, was killed along with two others," Maku governor, Hamid Ahmadian was quoted as saying.
Gas exports to Turkey were briefly halted due to a blast on Friday. The pipeline was swiftly repaired and gas flows were resumed on Saturday.
So far, no group has claimed responsibility for the blast.
But the official Iranian news agency said Iranian Kurdish rebel group PJAK was believed to have been responsible.
Sabotage is common on pipelines leading into Turkey from Iran and Iraq, where Kurdish separatist militants operate.
Iranian security forces have regularly fought rebels from PJAK which has bases in the border provinces of neighboring Iraq.
PJAK is an offshoot of the Kurdistan Workers Party (PKK), which took up arms in 1984 to fight for an ethnic homeland in southeast Turkey. Both Tehran and Washington have called PJAK a terrorist organization.
Iran is Turkey's second-biggest supplier of natural gas after Russia, sending 10 billion cubic meters of gas each year. Turkey uses gas to fire half of its power plants.
(Writing by Ramin Mostafavi; Editing by Jon Hemming)