At least one Turkish soldier and three suspected members of the Kurdistan Workers' Party (PKK) have been killed in eastern Turkey.

In a statement on Sunday, the Turkish army blamed the violence on the Kurdish rebels.

According to reports from the Turkish Armed Forces (TSK), fighting erupted in the early hours of Sunday near the Kagizman town in eastern Kars province during an operation to capture Kurdish militants.

Two soldiers were wounded, one of whom later died in hospital, the army said, adding that the security forces had shot dead three PKK members.

Ankara is currently waging what it calls an "anti-terror" offensive against the ISIL terrorist group in Syria and PKK militants in northern Iraq and the southeast of Turkey.

But, so far, Turkish airstrikes have overwhelmingly concentrated on the separatist Kurdish rebels. The PKK for its part  has responded by tearing up a 2013 ceasefire and waging a bloody campaign against the security forces.

More than 40 members of the Turkish security forces have been killed in violence linked to the PKK since the crisis began on July 20, when a bomb attack blamed on Daesh left scores of pro-Kurdish activists dead in the southern Turkish town of Suruç..

Since Friday alone, at least eight members of the Turkish security forces have been killed in attacks blamed on PKK militants in the country's Kurdish-majority east and southeast regions.

Meanwhile, Turkish President Recep Tayyip Erdogan said on national TV that the fight against terror would "continue until doomsday."

"Our police, our soldiers buried hundreds of terrorists. But it's not enough. This struggle will continue. We shall not succumb to complacency," he added.

The Turkish government also declared a curfew in the Varto district of eastern Mus province following heavy clashes between the Turkish army and PKK militants, the official Anatolia news agency said.

The clashes erupted overnight after the PKK militants demolished a bridge with bulldozers they had seized from Turkish forces, according to the state-run news agency.

The PKK, designated as a terrorist organization by Turkey, the European Union and the United States, took up arms for self-rule in the southeast in 1984 and the conflict has since claimed tens of thousands of lives.