Turkey rally
People react after an explosion during an election rally of pro-Kurdish Peoples' Democratic Party (HDP) in Diyarbakir, Turkey, June 5, 2015. Reuters/Sertac Kayar

Turkey's Kurdish-rooted opposition party, which could scuttle Tayyip Erdogan's ambitions for sweeping new powers, accused the President on Saturday of a lack of respect for supporters killed in a bomb attack in an election rally and demanded he apologize.

Erdogan countered by accusing Peoples' Democratic Party (HDP) leader Selahattin Demirtas of instigating violence in October, linked to events in Syria, that killed dozens.

Chanting "Murderer Erdogan" and bearing a banner declaring "peace despite everything,” hundreds marched to the scene of Friday's attacks in the mainly Kurdish southeastern city of Diyarbakir.

Others joined a convoy of cars heading to a funeral for a 16-year-old boy. Onlookers made the victory sign and chanted "martyrs don't die" and "AKP you will pay for this.”

HDP deputy Idris Baluken told Reuters his party had told the government it believed anti-HDP rhetoric from Erdogan and the AK Party had paved the way for the attacks.

Two explosions sent ball bearings and nails tearing into a crowd of tens of thousands at Friday, killing two people and injuring over 200.

Demirtas said Erdogan went ahead with his own rally after news of the bombing broke without referring to it or to the people affected.

Erdogan later offered his condolences on what he termed a "provocation" designed to undermine Sunday's election. He did not spell out who he believed to be the provocateur.

"He needs to apologize to them, express his sadness to them," Demirtas told a rally on the Asian side of Istanbul.

"He should go to Diyarbakir. Is he not the president of 77 million people? He ought to leave flowers where people were killed."

Erdogan, the most popular politician in Turkey but accused by opponents of authoritarian tendencies, seeks a large majority for the ruling AK Party on Sunday to furnish him with the powerful presidency he believes Turkey must have. However, if the HDP clears a 10 percent hurdle to enter parliament, that could rob AK of dozens of seats and thwart his ambitions.

"ANSWER AT THE BALLOT BOX"

Polls suggest such a result is within the HDP's grasp, drawing as the party now is on non-Kurdish center-left and secularist sympathizers as Erdogan's religious tone has become more pronounced.

At a rally in eastern Turkey, Erdogan said it was Demirtas who should apologize, accusing him of instigating violence that broke out when Kurds in the town of Kobani, just across the Syrian border, came under siege from Islamic State militants.

Demirtas accused pro-government newspapers of giving scant coverage of Friday's attacks. He held up their front pages as he spoke to thousands from atop a campaign bus in Istanbul.

"I know we are angry, but we will not act in anger. We will act in good conscience. We will be smart and we will give our answer at the ballot box and stand up for our country," he said.

Demirtas said his party has been the target of 140 violent attacks during the campaign, including a double bombing in southern Turkish cities last month which wounded six.

He says the HDP will continue to promote peace talks between Kurdish rebels and the government whatever the election outcome.

Erdogan has accused the HDP of being a front for the Kurdistan Workers Party (PKK), which took up arms in 1984 in an insurgency that has killed 40,000 people.

Jailed PKK leader Abdullah Ocalan and Ankara launched peace talks more than two years ago.

(Additional reporting by Seyhmus Cakan in Diyarbakir; Writing by Daren Butler; Editing by David Dolan, Ralph Boulton)