Turkish forces killed four Kurdish rebels Sunday, bringing to 53 the number of rebels killed since the launch of a major offensive in the mainly Kurdish southeast three days ago.

Four Kurdish rebels were killed in clashes in the Cukurca region in the southeastern Hakkari province, the military announced in a written statement posted on its website.

One Turkish soldier was also killed in the fight, it added.

The Turkish military launched air and land operations against the Kurdistan Workers' Party (PKK) after the separatist group's guerillas killed 24 soldiers and wounded 18 along the Iraqi border last week, the army's biggest losses since 1993.

The army earlier said "a total of 49 terrorists were rendered ineffective."

Some 10,000 troops on the ground are involved in Turkey's operations, backed by jets and helicopters, inside Turkey and across the border. Military officials did not say how many troops had entered Iraq.

But it said the operations were mainly concentrated inside the country.

Clashes between the PKK and the army have escalated since the summer.

The latest assaults have also mobilised the Turkish civil society.

Representatives of 24 nongovernmental organisations will hold a protest march in Istanbul on October 30 to denounce terrorism, Turkish media reported.

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

Turkey's last ground incursion into northern Iraq, an autonomous Kurdish region, was in February 2008, when the army struck the Zap region.