Two Turkish soldiers were killed in a clash with Kurdistan Workers Party (PKK) fighters in eastern Turkey at the weekend, the military said, as conflict continued despite a PKK ceasefire call.

The PKK announced its ceasefire on Saturday in response to calls to lower tensions ahead of a Nov. 1 election, telling militants to act only if they face an attack in a move three months after it ended a two-year-old ceasefire.

Hours earlier, two suicide bombers launched an attack on a rally of pro-Kurdish and leftist activists at Ankara's main train station, which a pro-Kurdish party said killed 128 people.

On Sunday, the Turkish military said its warplanes struck PKK targets in northern Iraq and southeastern Turkey over the weekend.

Late in the day, it said an operation had been launched against militants in the eastern province of Erzurum. Two soldiers were wounded on Sunday and died after being ferried by helicopter to hospital, the general staff statement said.

Security sources said some 30-35 PKK guerrillas were killed in northern Iraqi raids on Sunday while the military said 14 militants were killed in the district of Lice in the southeastern province of Diyarbakir.

Unrest continued elsewhere in the mainly Kurdish region, with the historic Sur district of Diyarbakir city remaining under round-the-clock curfew for the third day on Monday after police on Sunday fired tear gas to prevent protesters entering the district, witnesses said.

Before the widely expected ceasefire was announced, Deputy Prime Minister Yalcin Akdogan had dismissed it as a "tactic" ahead of the election, reiterating government demands that the militants lay down arms and leave Turkey.

The PKK's 31-year-old conflict with the state erupted anew in July, with Turkey launching air strikes on militant camps in response to attacks on its security forces, ending a March 2013 ceasefire. Hundreds have been killed in the latest fighting.

Designated a terrorist group by Turkey, the United States and European Union, the PKK launched a separatist insurgency in 1984 in which more than 40,000 people have been killed. The state launched peace talks with its jailed leader in 2012.