Kurdish militants began to withdraw from Turkey on Wednesday, May 8 pursuing a peace process meant to end a three-decade insurgency that has killed 40,000 people, ravaged the region's economy and tarnished the country's image abroad, Reuters said.

Turkish security forces manned checkpoints along the mountainous border with Iraq, keeping watch as the agreed pullout started by the first small groups of up to 2,000 Kurdistan Workers Party (PKK) fighters.

The withdrawal, ordered late last month by top PKK commander Murat Karayilan, is the biggest step yet in a deal negotiated by the group's jailed leader Abdullah Ocalan with Turkish officials to end almost 30 years of conflict.

The PKK has accused the army of endangering the pullout with reconnaissance drones and troop movements they said may trigger clashes. But there was no sign of military activity in the grey skies over southeast Turkey.

Security sources did not confirm the withdrawal. Fighters are accustomed to moving furtively and are expected to move in groups of around half a dozen in a process likely to take several months.

The PKK force is small but dogged, with 3,000-4,000 fighters based in Iraq and 1,500-2,000 in Turkey, where they have targeted Turkish troops as well as bombed cities including Istanbul and beach resorts.

The withdrawal will be monitored on the Turkish side by the MIT intelligence agency and across the border by the Kurdish regional government of northern Iraq.

The first fighters were expected to arrive at PKK bases in northern Iraq within a week.