An explosion overnight on the Kirkuk-Ceyhan pipeline, which carries about a quarter of Iraqi crude exports, has knocked out flows and repairs are expected to take up to 10 days, Turkish Energy Ministry officials said on Monday.

The blast occurred in Mardin province, north of Turkey's border with Syria, the officials said on condition of anonymity.

The outlawed Kurdistan Workers Party (PKK) was behind the attack, according to Firat news agency, which is close to the rebels.

A fire caused by the explosion continued to burn on Monday, security sources said.