Turkey's government said on Monday Islamic State was the prime suspect in suicide bombings that killed at least 97 people in Ankara, but opponents vented anger at President Tayyip Erdogan at funerals, universities and courthouses.
Prime Minister Ahmet Davutoglu said Saturday's bombing, the worst of its kind on Turkish soil, was intended to influence the outcome of November polls Erdogan hopes will restore the AK party he founded to an overall parliamentary majority. There is no question of postponing the vote, officials have said.
"It was definitely a suicide bombing," Davutoglu said in an interview broadcast live on Turkey's NTV. "DNA tests are being conducted. It was determined how the suicide bombers got there. We're close to a name, which points to one group."
Opponents of Erdogan, who has led the country over 13 years, blame him for the attack on a rally organized by pro-Kurdish activists and civic groups, accusing the state at best of intelligence failings and at worst of complicity by stirring up nationalist, anti-Kurdish sentiment.
The government, facing a growing Kurdish conflict at home and the spillover of war in Syria, vehemently denies such accusations.
The sheer range of possible perpetrators - from Islamic State and Marxist radicals to militant nationalists and Kurdish armed factions - highlights fissures running through Turkish society. At stake is the stability of NATO country seen by the West as a bulwark against Middle Eastern turmoil.
Hundreds chanting anti-government slogans marched on a mosque in an Istanbul suburb for the funeral of several of the victims, attended by Selahattin Demirtas, leader of the pro-Kurdish parliamentary opposition Peoples' Democratic Party (HDP), which says it was the target of the bombings.
Riot police with water cannon and armored vehicles stood by as the crowd, some chanting "Thief, Murderer Erdogan" and waving HDP flags, moved towards the mosque in the working class Umraniye neighborhood of Istanbul.
Several labor unions also called protests. Hundreds of people, many wearing doctors' uniforms and carrying Turkish Medical Association banners, gathered by the main train station in Ankara where the explosions happened to lay red carnations but were blocked by riot police, a Reuters witness said.
Lawyers at an Istanbul courthouse chanted "Murderer Erdogan will give account" as colleagues applauded, footage circulated on social media showed.
The HDP has put the death toll from the bombings at 128 and said it had identified all but eight of the bodies. Davutoglu's office has said 97 people were killed.
The bombs struck seconds apart as hundreds gathered for a march organized by pro-Kurdish activists and civic groups to protest over a growing conflict between Turkish security forces and Kurdistan Workers Party (PKK) militants in the southeast.
The HDP accused Ankara of escalating violence to try to weaken the HDP at Nov. 1 polls, regain an AK majority and pave the way for the more powerful presidential system Erdogan seeks. "Our electorates feel under constant threat in every social space and political activity they attend," it said.
It also accused the AKP of relying on radical groups including Islamic State as proxies to fight Kurds in northern Syria, a charge the government strongly denies.
The Haberturk newspaper reported police sources as saying the type of explosive and the choice of target pointed to a group within Islamic State known as the 'Adiyaman ones', referring to Adiyaman province in southeast Turkey.
Turkey is vulnerable to infiltration by Islamic State, which holds swathes of Syrian land abutting Turkey where some two million refugees live. But the group, not normally reticent about its attacks, made no claim to a similar bombing in the town of Suruc in July attributed to it; nor has it made any reference to the Ankara attack in internet postings.
Tensions have further unnerved investors, many of whom have reduced their Turkey exposure in recent months because of the election uncertainty. The lira weakened to 2.95 to the dollar early on Monday, making it the worst performing currency among major emerging markets.
HDP spokesman Ayhan Bilgen told Reuters his party, which expanded beyond its Kurdish voter base and drew in mainly left-wing opponents of Erdogan at the June vote, was considering cancelling all of its rallies due to the security concerns.
Saturday's march had been called to protest over the deaths of hundreds since the collapse in July of a ceasefire between security forces and the PKK, which is deemed a terrorist group by the United States and the EU as well as Turkey. Some 40,000 have been killed in the predominantly Kurdish southeast since the PKK's insurgency began in 1984.
A top PKK commander was reported by news website close to the group on Monday as saying its militants would stick to a ceasefire pledge announced at the weekend in memory of those who died in Ankara.
Firat news agency reported Murat Karayilan as saying in a radio broadcast to PKK fighters that they were not to stage attacks in Turkey unless they came under attack from the security forces.
The government has already dismissed the ceasefire declaration as an election gambit meant to bolster the pro-Kurdish HDP, saying the militants must disarm and leave Turkey. It continued air strikes on PKK camps over the weekend.
(Additional reporting by Gulsen Solaker and Orhan Coskun in Ankara; Writing by Nick Tattersall)