Turkey's Kurds on Monday marked the annual spring festival of Newroz with a call for the resumption of peace talks between the government and Kurdish militants, but four Turkish soldiers were killed in another rebel attack in the restive southeast region.

The appeal from the pro-Kurdish People's Democratic Party (HDP) for peace talks also coincided with a pledge from Turkish President Tayyip Erdogan to use all the country's military and intelligence might to crush terrorism following a spate of suicide bombings, two claimed by Kurdish militants.

Since last year's Newroz festival Turkey's mainly Kurdish southeast has seen a big upsurge in violence due to the collapse of a 2-1/2 year ceasefire in July between the Ankara government and militants of the outlawed Kurdistan Workers Party (PKK).

In the latest attack, PKK fighters launched a bomb attack on a military vehicle in the town of Nusaybin near the Syrian border, security sources said. The army said four soldiers were killed, while five soldiers and a police officer were wounded.

The attack came as Kurds marked the Newroz festival, a traditional rallying point for PKK supporters who on Monday waved party flags and pictures depicting their jailed leader Abdullah Ocalan as they gathered in a park on the outskirts of Diyarbakir, the region's largest city.

The revellers chanted "We will win by resisting!" "Long live Ocalan!" and "The PKK are the people, the PKK are here!" as music blared over the sound system.

"We are ready to take the initiative to return to the peace (talks) table," HDP co-leader Selahattin Demirtas said in a speech beneath pictures of Ocalan projected onto a screen.

"If they want to achieve a result by crushing with war and violence, bringing people to their knees, this will only bring chaos to our country," Demirtas told the crowd, which was smaller than in previous years.

At the 2015 Newroz celebrations, in a statement read out on his behalf, Ocalan had said the PKK's three-decade insurgency had become "unsustainable" and he had urged the rebels to hold a congress on laying down their weapons.

Since then fighting has returned to the peak levels of the 1990s, with hundreds killed across the southeast.

In Istanbul Erdogan, who regards the HDP as an extension of the PKK and wants to prosecute its lawmakers, warned against any attempt to stir up violence at the Newroz celebrations.

"I curse those who consider Newroz not as a festival but as (a time) for shedding blood," he said.

Turkish security fears have been fuelled by bombings which have killed more than 80 people in Ankara and Istanbul this year. Kurdish militants claimed the two suicide bombings in Ankara, though officials blamed Islamic State for a bombing that killed four people in Istanbul on Saturday.

Interior Minister Efkan Ala has said 200,000 members of the security forces are maintaining order across Turkey during Newroz, which is also celebrated in Iran and central Asia.

In Turkey this year celebrations have only been allowed in 18 of the country's 81 provinces due to the security problems.-Reuters