Turkey is targeting Islamic State in investigations of a double suicide bombing in Ankara that killed up to 128 people, officials said yesterday, while opponents of President Tayyip Erdogan blamed him for the worst such attack in Turkish history.

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 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 neighbouring Syria.

Islamic State fighters 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 Islamic State 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 Islamists.

Family members of a victim of Saturday’s bomb blasts mourn during a funeral ceremony in Ankara, Turkey, yesterday.

“All signs indicate that the attack may have been carried out by Isil [Islamic State]. We are completely focused on Isil,” one of the sources said.

However, Islamic State makes no claim to the Ankara attack

CHP Opposition leader Ahmet Kilicdaroglu, speaking after a meeting with Prime Minister Ahmet Davutoglu, said he had been told both suicide bombers were men.

State-run Anadolu Agency said police detained 43 suspects in operations targeting the Islamic State across Turkey from Sanliurfa in the southeast to Izmir in the west and Antalya on the south coast. It was not clear when they were held.

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 the Suruc bombing and has made no reference to the Ankara attack in internet postings

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. The scale of the casualties eclipsed attacks blamed on al-Qaeda in 2003 when two synagogues, the Istanbul HSBC Bank headquarters and the British consulate were hit, killing 62 people. Questions have been raised over whether a parliamentary election due on November 1 can be safely held.