"Today, the Guerrilla Forces took the responsibility of the sabotage action," wrote PKK spokesman Roj Welat from Iraq. Thousands of PKK members operate out of camps in the mountains of northern Iraq, in remote border regions that are beyond the control of the Iraqi government.

The blast follows two deadly clashes between Kurdish rebels and Turkish security forces on Tuesday, which left at least seven Turkish soldiers dead.

In a written statement, the governor of Turkey's eastern Agri province blamed Wednesday's early morning explosion on what he called a "separatist terrorist organization's members."

Turkish television showed images of a fire burning white hot in the night, illuminating the surrounding countryside.

An official from BOTAS, Turkey's state oil and gas company, speaking on condition of anonymity, told CNN that the fire had been extinguished. However, the official said, it will take at least six days to resume pumping fuel through the pipeline. In the meantime, BOTAS has increased the flow of gas from Azerbaijan to compensate for the gas cut.

Turkey is reeling from another bloody summer of clashes with the PKK, the latest in a conflict that has simmered for more than 25 years. More than 30,000 people, mostly ethnic Kurds, have been killed in the conflict.

Initially, the PKK fought to carve out a separate homeland for Turkey's ethnic Kurdish minority, which makes up roughly 20 percent of the Turkish population. But in recent years, the rebels have said they are giving up their demands for an independent Kurdish state, and are instead fighting for more linguistic and cultural freedoms. Though the Kurds represent Turkey's largest ethnic minority, their language has historically been suppressed by the Turkish state, which long referred to Kurds as "mountain Turks."

"If the military operations and the political operations do not stop against the guerrillas and the Kurdish people, the actions of the PKK will spread to the cities as well," Welat told CNN in a telephone call last month.

In his e-mail Wednesday, Welat announced a new proposal to disarm thousands of PKK fighters and send them back to their homes in Turkey, under the auspices of the United Nations.

"To do this, first of all there has to be a bilateral ceasefire," Welat wrote. The PKK also wants other conditions, including the release of Kurdish prisoners -- including PKK leader Abdullah Ocalan -- and the formation of an independent truth and reconciliation commission modeled on post-apartheid South Africa.

A senior Turkish government official, speaking on condition of anonymity, said it was unlikely Turkey would respond to the proposal. Ankara has long refused to negotiate or communicate with what it officially considers to be a terrorist organization.

On Tuesday, the Turkish military announced that six soldiers were killed and nine more wounded after rebels launched a pre-dawn attack on troops operating in the eastern province of Hakkari. In a separate incident, the military said a soldier was killed after coming under fire in Van, another eastern Turkish province.