The mine, believed to have been placed by outlawed Kurdistan Workers' Party (PKK) rebels, exploded as a military patrol vehicle was passing on a road between the provinces of Tunceli and Elazig, the source, speaking on condition of anonymity, said.

One of the soliders was seriously wounded in the attack.

The PKK, which has been waging a 25-year campaign for self-rule, often employs mines and home-made bombs set off by remote control in attacks targeting Turkish security forces.

In a separate development, the Anatolia news agency reported Friday that police had arrested four suspects believed to be linked to the PKK preparing for a bomb attack in the western city of Izmir.

Police found a bomb in the car in which the suspects were caught in the city's Buca district which has a large Kurdish community, the report added. It did not say when the arrests took place.

Although the rebels' main theatre of operations is southeast Turkey, they have in the past carried out bombings in cities and tourist resorts in the country's west.

The arrival of spring has brought a rise in violence between Turkish forces and PKK rebels operating out of bases in Turkey and neighbouring northern Iraq.

Some 45,000 people have been killed since 1984 when the PKK, listed as a terrorist group by Turkey and much of the international community, took up arms for self rule in Turkey's Kurdish-majority southeast.