ISTANBUL (AP) — Authorities say fighting between Turkish forces and Kurdish rebels in the restive southeast of the country has killed eight Turkish soldiers and 35 Kurdish fighters.

The office of Turkey's General Staff headquarters said Saturday the eight soldiers were killed in a clash Friday afternoon with Kurdish militants at a checkpoint in the southeastern Hakkari province. A subsequent operation against the Kurdish rebels left eight Kurds dead, the military said.

Separately, a further 27 fighters from the Kurdish Workers' Party, or PKK, were killed in the same province when Turkish troops launched an air-and-ground operation against groups of PKK fighters attempting to infiltrate early Saturday, the state-run Anadolu news agency said, quoting the military.

The PKK reportedly bombed a freight train in the eastern province of Elazig on Saturday, planting an improvised device on the tracks that caused damage but no casualties, Anadolu said. Security forces have begun an operation in the area to apprehend those responsible.

Turkish forces have been fighting the PKK for decades, with armed clashes resuming after a 2 1/2 year cease-fire collapsed in mid-2015.