An attack on a pipeline in eastern Turkey has halted the flow of Iranian gas into the country, Turkey's energy ministry has said, adding that it may take up to a week before it will be operating again.

"Work continues to put out the fire," the governor's office in Agri province said in a statement quoted by the Anatolia news agency.

"It has been established that the incident was caused by a terrorist attack."

The governor's office said Kurdish fighters, who are seeking autonomy in Turkey's southeast, were suspected of sabotaging the pipeline.

Firefighters were sent to the site of the explosion, which took place at 11:10 pm on Thursday, and the pipeline was shut off.

A Turkish energy ministry official speaking on condition of anonymity told the AFP news agency that repairs on the pipeline had started and would last about a week.

The shortfall in Iranian gas would be compensated by deliveries from Azerbaijan, and Russia via the undersea Blue Stream pipeline.

Turkey receives between 15 and 18 billion cubic metres of gas a day via the Iranian pipeline, which links the western city of Tabriz with the Turkish capital.

Fighters from the outlawed Kurdistan Workers' Party (PKK) are regarded as terrorists by Turkey, the European Union and the United States.

The PKK, which often attack pieplines, want constitutional recognition for the Kurds, regional self-governance and Kurdish-language education in schools.

Late last month, gas exports from Iran to Turkey were briefly halted due to a blast. The pipeline was swiftly repaired and gas flows were resumed a day later. 

More than 45,000 people have been killed since the PKK launched its armed campaign against the Turkish state in 1984.