Government officials made clear that despite alarm over the attack on a rally of pro-Kurdish activists and civic groups, there would be no postponement of November polls Erdogan hopes can restore an overall majority for the AK Party he founded.
Thousands of people gathered near the scene of the attack at Ankara's main railway station, many accusing Erdogan of stirring nationalist sentiment by his pursuit of a military campaign against Kurdish militants, a charge Ankara vehemently rejects.
"Murderer Erdogan", "murderer police", the crowd chanted in Sihhiye square, as riot police backed by water cannon vehicles blocked a main highway leading to the district where parliament and government buildings are located.
The pro-Kurdish Peoples' Democratic Party (HDP), a major presence at Saturday's march and holding seats in parliament, said police attacked its leaders and members as they tried to leave carnations at the scene. Some were hurt in the melee, it said in a statement.
The attacks have shocked a nation beset by resurgent conflict with the militant Kurdistan Workers Party (PKK) in its southeast and increasingly threatened by spillover from the war in neighboring Syria.
ISIL militants are encamped close to its borders, which mark also the frontier of the NATO alliance, and last week Russia launched air strikes in Syria, its planes violating Turkish air space on several occasions.
Two senior security sources said initial signs suggested ISIL was behind the Ankara attack, and that it bore striking similarity to a July suicide bombing in Suruc near the Syrian border, also blamed on the radical group.
"All signs indicate that the attack may have been carried out by ISIL. We are completely focused on ISIL," one of the sources told Reuters.
CHP opposition leader Ahmet Kilicdaroglu, speaking after a meeting with Prime Minister Ahmet Davutoglu, said he had been told both suicide bombers were men.
The HDP, which expanded beyond its Kurdish voter base and drew in mainly left-wing opponents of Erdogan at June elections, said the death toll had risen to 128 and that it had identified all but eight of the bodies.
The prime minister's office said late on Saturday that 95 people had been killed.