Tuesday's bombing ripped through a section of the conduit near the village of Midyat in Mardin province in southeastern Turkey, killing two civilians and halting the flow of oil.

"The blaze was extinguished and the oil flow has restarted," a spokeswoman from Turkey's state-run oil and gas company BOTAS told AFP.

The conduit linking Kirkuk in northern Iraq to the port of Ceyhan on Turkey's Mediterranean coast consists of two parallel pipelines that allow authorities to switch oil flow between the two if one is damaged.

The spokeswoman added that they expected repairs on the damaged pipeline to take about 10 days.

A local security source told AFP that BOTAS teams had begun damage-assessment work on the pipeline ahead of actual repairs, with paramilitary troops providing security for them.

The outlawed Kurdistan Workers' Party (PKK), which has waged a 26-year armed campaign against Ankara, has claimed responsibility for the bombing, the pro-Kurdish Firat news agency said on Thursday. It gave no details.

Turkish authorities had immediately blamed the attack on the PKK which has bombed the conduit several times, including last month.

The 970-kilometre (600-mile) Turkish-Iraqi pipeline is one of the main export routes for Iraqi crude. Once the oil reaches Ceyhan, it is loaded onto tankers and shipped to world markets.

The conduit, first inaugurated in 1976, carried 167.6 million barrels of oil last year, according to Turkish statistics.

The PKK, listed as a terrorist group by Turkey and much of the international community, took up arms for self-rule in the Kurdish-majority southeast in 1984, sparking a conflict that has claimed around 45,000 lives.

It has significantly stepped up attacks since its jailed leader Abdullah Ocalan declared in May that he was abandoning efforts to seek dialogue with Ankara.