The incidents, in the southeast and east of the country where the outlawed Kurdistan Workers' Party (PKK) is active, were caused by remote-controlled mines which the sources said were planted by PKK rebels.

The first saw a minibus carrying civilians and "village guards" -- a government-armed Kurdish militia supporting the army in the fight against the PKK rebels -- blown up at Sason, in the southeastern province of Batman, the governor's office said in a statement.

Three village guards were killed on the spot while five people were injured, the statement said. One of the injured later died in the local hospital, a source from the hospital said.

The second, in Siirt province in the country's southeast, saw a military convoy hit, injuring a soldier and a village guard, according to a security source.

In the third blast, three soldiers were injured when their vehicle hit a mine on rural ground in the eastern province of Bingol, local security sources said.

Remote-controlled mines are a frequent element in the PKK armoury.

Listed as a terrorist group by Turkey and much of the international community, the PKK has been fighting for self-rule in Turkey's mainly Kurdish southeast since 1984. The conflict has claimed more than 37,000 lives.

Turkish warplanes have also been bombing PKK positions in northern Iraq on and off since mid-December, following parliamentary authorisation for cross-border military action.

In February, the army conducted a week-long first ground offensive against rebel hideouts in the region, where Ankara estimates more than 2,000 militants take refuge.