Members of the rebel Kurdistan Workers' Party (PKK) opened fire on a convoy near the town of Baskale, killing three soldiers and wounding a fourth along with a local official and a bodyguard, the sources said.

Clashes between security forces and PKK militants have surged since the June 12 elections.

Many Kurdish-backed lawmakers boycotted the new parliament after authorities refused to release six Kurdish activists who were elected while awaiting trial in prison and stripped one of them of his parliamentary seat.

On June 16, 13 soldiers were killed in Diyarbakir province, the worst loss of life for the army since October 2008. Seven PKK rebels were also killed in the assualt.

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