"Turkish soldiers from two separate points in Cukurca town crossed into south Kurdistan to follow (rebels)," said Firat news agency, which is known as a mouthpiece of the Kurdistan Workers' Party (PKK).

A battalion of Turkish soldiers launched an operation inside northern Iraq, it said.

A battalion numbers more than 600 soldiers in the Turkish army.

"Turkish ground forces are attempting to cross the Iraqi border at Jeli, in the Hakkari region" of southeast Turkey, Dozdar Hammo, a spokesman for the PKK, told AFP.

Hammo said that PKK forces had so far blocked Turkish forces, and claimed they killed 50 Turkish soldiers.