Turkish investigators were on Tuesday seeking to firm up suspicions that Islamic State (IS) jihadists were behind the double suicide bombings in Ankara that killed 97, as President Recep Tayyip Erdogan was due to break days of silence over the blasts.

Prime Minister Ahmet Davutoglu said Monday that the IS group was the prime suspect for the attack, Turkey's deadliest ever, which targeted a rally of labor, leftist and Kurdish activists.

Thousands of people took to the streets of Ankara on Sunday to denounce the government of President Recep Tayyip Erdogan after 95 people were killed in twin suspected suicide bombings on a peace rally, Turkey's worst ever terror attack.

Prime Minister Ahmet Davutoglu declared three days of national mourning, with flags flying at half mast across the country, as questions grew over who could have ordered the Ankara bombings.

Turkish President Recep Tayyip Erdogan's son Bilal on Wednesday said he had temporarily moved to Italy to complete his doctoral studies but denied fleeing Turkey after being implicated in a corruption scandal.

Bilal was one of the main protagonists implicated in corruption allegations that exploded in December 2013 against the president's inner circle and were bitterly denied by Erdogan, then premier.

The Russian air campaign in Syria has thrown an immense obstacle in the way of President Recep Tayyip Erdogan's vision for the future of the country, enraging the Turkish leader and leaving Ankara increasingly sidelined.

Russia's air strikes are aimed at propping up the regime of President Bashar Assad, the very ruler who Turkey has for years insisted must be ousted if there is to be any solution to the Syrian crisis.

Turkish President Recep Tayyip Erdogan and EU head Donald Tusk said Monday they had discussed Ankara's controversial plan for a safe zone cleared of Islamic State jihadist fighters in northern Syria.

"The European Union is ready to take up all issues with Turkey so we also discussed a possible buffer zone in Syria," Tusk said after meeting Erdogan for talks in Brussels dominated by the migrant crisis and the Syrian conflict.

Turkish President Recep Tayyip Erdogan on Saturday urged Russian counterpart Vladimir Putin to reconsider Moscow's bombing campaign in Syria, accusing the Russian military of turning a blind eye to the killing of dozens of civilians.

Speaking in an interview with Al-Jazeera Arabic, Erdogan expressed anger that whereas Moscow had informed Ankara it would be attacking Islamic State (IS) jihadists in Syria, it had in fact targeted moderate Syrian rebels.

Syria cannot be forced to choose between President Bashar Assad and "terrorist groups" like the Islamic State (IS) organization, Turkish President Recep Tayyip Erdogan said Thursday.

Erdogan -- who has always rejected cooperation with Assad as a solution in the fight against IS -- was addressing the Turkish parliament as Russia launched air strikes in Syria in support of the regime.

Turkish President Recep Tayyip Erdogan vowed Tuesday there would no let-up in operations against Kurdish rebel strongholds, after a cross-border raid this week killed more than 30 militants.

"We will not stop," Erdogan said in a televised speech in Ankara, adding that operations by Turkey's security forces in the southeast of the country and in northern Iraq would continue "without pause."

Turkish President Recep Tayyip Erdogan came to Saudi Arabia's defense on Friday as blame shifted towards the Saudi authorities after a stampede at the hajj pilgrimage killed at least 717 people. 

"I do not sympathize with the hostile statements against Saudi Arabia," Erdogan told journalists.

Turkish President Recep Tayyip Erdogan, a fierce critic of Bashar Assad, on Thursday suggested for the first time that the Syrian president could have a role to play in a future political transition.

"The process could possibly be without Assad, or the transitional process could be with him," Erdogan told reporters after Eid prayers in Istanbul, when asked about a possible solution to Syria's four-year civil war.