Kurdish activists waging a 24-year armed campaign against the Ankara government claimed responsibility for the blast, but Guler said there was no indication so far of foul play.

Inaugurated in 2006, the 1,774-km BTC pipeline carries Azeri oil from the Caspian Sea fields to Turkey's Mediterranean port of Ceyhan, and is capable of transporting 1.2 million barrels of crude per day.

Oil tensions

Oil supplies have faced further threats with tensions in Georgia's breakaway region of South Ossetia escalating into a full-blown military conflict between Moscow and Tbilisi.

Last week, Georgia claimed that Russian warplanes bombed the pipeline, but Moscow denied deliberately targeting it.

British oil company BP PLC has also stopped using a railway line that exports Azeri oil through Georgia, following reports of damage to the line, which can carry between 50,000 and 70,000 barrels of oil a day.

Georgian officials accused Russia of blowing up a key railway bridge on the line on Saturday, severing the country's main east-west rail route. Officials later vowed to restore the link within a week.

The problems on the railway line compound BP's decision last week to shut down its Baku-Supsa oil pipeline, which runs through the centre of Georgia from Baku in Azerbaijan to Supsa on the Black Sea coast.