Turkey has said Islamic State (IS) 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 Mr 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.

Mr Davutoglu said: "It was definitely a suicide bombing. 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 Mr Erdogan, who has led the country over 13 years, blame him for the attack on a rally organised by pro-Kurdish activists and civic groups, accusing the state at best of intelligence failings and at worst of complicity by stirring up 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 IS and Marxist radicals to militant nationalists and Kurdish armed factions - highlights fissures running through Turkish society.

At stake is the stability of a Nato member 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 armoured vehicles stood by as the crowd, some chanting "Thief, Murderer Erdogan" and waving HDP flags, moved towards the mosque in the working class Umraniye neighbourhood of Istanbul.

Several labour 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.

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. Mr Davutoglu's office has said 97 people were killed.

The bombs struck seconds apart as hundreds gathered for a march organised 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 south-east.

The HDP accused Ankara of escalating violence to try to weaken the HDP at the polls in November, regain an AK majority and pave the way for the more powerful presidential system Mr 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 IS as proxies to fight Kurds in northern Syria, a charge the government strongly denies.