An explosion overnight on a pipeline carrying about a quarter of Iraqi crude exports from oilfields near the city of Kirkuk has knocked out flows and repairs are expected to take up to 10 days, Turkish Energy Ministry officials said on Monday.
Exports at the terminus in Ceyhan on Turkey's Mediterranean coast were unaffected because of reserves that were held at the port, a source at the Iraqi North Oil Company said.
The outlawed Kurdistan Workers Party (PKK) was behind the attack, according to Firat News, which is close to the rebels.
The PKK has repeatedly attacked the link, calling it a strategic asset, in its 28-year campaign against the Turkish state. More than 40,000 people have died in the militants' fight for more autonomy for Turkey's estimated 14 million ethnic Kurds.
The blast occurred in Mardin province, north of Turkey's border with Syria.
Exports along the Kirkuk-Ceyhan pipeline have been running at around 300,000 barrels per day, the Iraqi official said.
A Turkish official said only one of the two pipes in the 600-mile double link was damaged, and engineers were assessing whether flows can be resumed on one of the pipes.
Officials at the NOC said the second pipe would take at least 24 hours to become operational again.
A fire caused by the explosion continued to burn on Monday, security sources said.