ANKARA, Turkey - Turkey's top military commander threatened Saturday to make Iraq-based Kurdish rebels "grieve with an intensity that they cannot imagine,'' while the prime minister said his country would not bow to international pressure over the issue.

The military chief, Gen. Yasar Buyukanit, said Friday that Turkey would wait until Prime Minister Recep Tayyip Erdogan meets with President George W. Bush in Washington on Nov. 5 before deciding on any cross-border offensive.

But Erdogan said his country could not be pinned down by dates in deciding whether to attack.

"We can't say when or how we will do it, we will just do it,'' he said.

Clashes between government forces and guerrilla fighters have been escalating since the rebels broke a ceasefire in 2004.

Fighters of the Kurdistan Workers' party, or PKK, have killed at least 42 people in the last month, including some 30 Turkish soldiers in two ambushes that were among the boldest attacks in years.

"We are determined to make those who cause this sadness grieve with an intensity that they cannot imagine,'' Buyukanit said.

His comments come amid an increasing nationalist fervour in Turkey, with the country's red flag draped over scores of balconies, displayed in the backs of cars, and sold by vendors walking the streets.

Thousands took to the streets of several Turkish cities, condemning the PKK and pushing for military action.

Some 1,000 people chanted "down with the U.S.A., down with the PKK'' outside the U.S. Embassy in Ankara and said they were ready to fight the Kurdish rebels, yelling "we're all soldiers.''

Hundreds more people marched in Istanbul, while another 1,500 _ mostly children _ took to the streets of the predominantly Kurdish city of Sirnak, in southeastern Turkey near the Iraqi border.

Military helicopters shuttled more troops into the mountains near Iraq, while patrols secured roads and checkpoints.

In a show-of-force exercise about 30 kilometres from the border, near the village of Ikizce, a group of Turkish tanks fired 10 rounds into the mountains toward Iraq.

Elsewhere, Turkish forces shelled two Iraqi areas along the western portion of the 330-kilometre border, said Col. Hussein Tamr, an Iraqi border guard officer.

Meanwhile, the PKK indicated it might release eight Turkish soldiers it captured in an operation on Oct. 21 in response to calls by a Kurdish member of the  Turkish Parliament.

Speaking in the northern Iraqi city of Sulaimaniyah, PKK spokesman Abdul-Rahman Al-Chaderchi said the group was working on a response. "Within a short time we will end the issue of the captives,'' Al-Chaderchi told The Associated Press.

A military campaign in Iraq could derail one of the few stable areas in Iraq, and trap the United States in an awkward position between key allies: NATO-member Turkey, the U.S.-backed Baghdad government and the self-governing Iraqi Kurds in the north.

Talks between Iraqi and Turkish official on Friday failed to produce any breakthroughs and the Iraqi delegation returned home Saturday.