The separatist Kurdistan Workers' Party (PKK) said the explosion was "an act of sabotage" by its militants, details of which would be revealed later, according to the report, seen on the website of the Firat news agency.

The blast occurred Tuesday night in a pump at a section of the pipeline near the eastern town of Refahiye, in Erzincan province.

The PKK, listed as a terrorist group by Ankara and much of the international community, has sabotaged gas and oil pipelines in the past as part of its 24-year armed campaign for self-rule in Turkey's mainly Kurdish southeast.

An official from Turkey's state-run oil and gas company BOTAS told Anatolia news agency Thursday that no trace of a sabotage had been found but a definite conclusion could be made only after the fire at the pipeline was extinguished.

The pipeline is expected to remain shut for about 15 days for repair works.

Inaugurated in 2006, the BTC pipeline carries oil from the Caspian Sea fields to Turkey's Mediterranean port of Ceyhan, from where tankers transport the crude to Western markets.