A large group of militants from the outlawed Kurdistan Workers' Party (PKK), armed with assault rifles, attacked the outpost near Nazimiye town, Tunceli province late Friday, triggering a gunfight that lasted until the early hours of Saturday.

One of the slain soldiers was the commander of the outpost. Two of the wounded soldiers were in a critical condition and were being treated at a military hospital in a neighbouring province.

Several Kurdish rebels were believed to have been killed in the exchange of fire, the source said, speaking on condition of anonymity. He did not give a figure.

The army dispatched additional troops and attack helicopters to the mountainous area early Saturday to hunt down the attackers, he added.

The PKK, listed as a terrorist group by Ankara and much of the international community, took up arms against Ankara in 1984, sparking a conflict that has claimed about 45,000 lives.

Winter lulls in the conflict are usually broken with the arrival of spring when the snow melts, allowing the rebels to move out from their mountain hideouts in Turkey and neighbouring Iraq.

Last year, the Turkish government announced steps to expand Kurdish freedoms in return for ending the PKK insurgency, but the plan has faltered amid the banning of Turkey's main Kurdish political party in December and a number of bloody rebel attacks.

In December, Kurdish rebels killed seven soldiers and wounded three others when they ambushed a military vehicles in the north of the country.