spokesman said.
Rallies in the wake of the bombings have been hugely critical of President Recep Tayyip Erdogan, with demonstrators chanting slogans like “Erdogan murderer” and accusing the government of failing to prevent the attacks.
“We lost many friends. But the government must know that we will not step back. We will continue to fight and will fight even harder,” union activist Vassaf Turgut told AFP in Ankara.
But Davutoglu denied there had been any security or intelligence failure and dismissed fears Turkey could be facing civil war.
“This attack will not turn Turkey into Syria,” he said.
In his first reaction to the violence, Turkey’s leading writer Orhan Pamuk in an interview with Italian daily La Repubblica warned of sectarian conflict and blamed Erdogan for the insecurity.
Erdogan, in a written statement, has condemned the “heinous” attacks as an attempt to break the country’s unity.
However the Turkish strongman has remained uncharacteristically silent in public since the attacks. On Monday was holding closed door meetings with officials including with spy chief Hakan Fidan, army head Hulusi Akar and Davutoglu.
The attacks came with Erdogan under huge political pressure as Turkey heads into the November 1’s snap election.
His ruling Justice and Development Party (AKP) failed to keep its overall majority in June 7 polls and then could not form any coalition.
Erdogan called a repeat election for November 1 but opinion polls are showing that that the result appears likely to be much the same as before.
Some commentators suggested that the Ankara attack could prompt the government to postpone the polls but Davutoglu insisted they would go ahead “under whatever circumstances”.
AKP spokesman Omer Celik said that the party had cancelled all campaign rallies until Friday and thereafter would hold “anti-terror” unity rallies.
Turkish media said investigators believe the type of bombs used in Ankara were similar to the one used in a July 20 suicide bombing in the town of Suruc on the Syrian border that killed 34 also mostly Kurdish and leftist activists. That attack was quickly blamed on IS.
The Hurriyet daily reported that the authorities had taken DNA samples from families of 16 people suspected of being members of the IS group.
They are also examining the theory that the missing elder brother of the Suruc suicide bomber Abdurrahman Alagoz could have carried out one of the suicide attacks, it added.
Turkish authorities have since Sunday arrested over 40 suspected members of IS across the country, but it is unclear if the raids had any link with the Ankara attacks.
The Suruc bombing caused one of the most serious flare-ups in Turkey in recent times as the PKK accused the government of collaborating with IS and resumed attacks on the security forces after a truce of more than two years. The military hit back, launching a “war on terror” against the Kurdish militants.
The PKK on Saturday announced it would suspend all attacks -- except in self defence -- ahead of the polls. But the Turkish army kept up its campaign with more air raids killing 17 suspected militants in the southeastern Hakkari region on Sunday, state media said.