By Humeyra Pamuk and Nick Tattersall
ISTANBUL (Reuters) - President Tayyip Erdogan said on Thursday Syrian intelligence and Kurdish militants, not just Islamic State, were behind a double suicide bombing in Ankara which killed more than 100 people, the worst attack of its kind in Turkey's modern history.
Erdogan said Kurdistan Workers Party (PKK) militants, the Syrian "mukhabarat" secret police and the Syrian Kurdish PYD militia had worked together with Islamic State in the bombing on Oct. 10.
Turkish authorities have focussed their investigation on a home-grown Islamic State cell, but the government has been more ambiguous about assigning blame, concerned, its critics say, about how the fallout might impact a general election on Nov. 1.
"This incident shows how terror is implemented collectively. This is a completely collective act of terror and it includes ISIS (Islamic State), PKK, the mukhabarat, and the terrorist group PYD from north of Syria," Erdogan said.
"They carried out this act all together," he said in a speech broadcast live on Turkish television at the annual meeting of a labour union in Ankara. Erdogan has often cast threats to Turkey or his own authority as foreign-backed plots.
Opponents accuse the state of a massive intelligence failure before the bombings and say Erdogan is trying to deflect blame.
The prime suspects in the attack were part of a suspected Islamic State cell in the southeastern town of Adiyaman who were known to the authorities, responsible for previous attacks, and in some cases reported by their own families.
One of the two bombers has been identified as Yunus Emre Alagoz, the state-run Anadolu Agency said on Monday. Alagoz is thought to have been a key member of the so-called "Adiyaman cell" whose brother blew himself up in the town of Suruc in July, killing 33 people, an attack also blamed on Islamic State.
"Either we're being protected by the world's worst intelligence and security agencies or there is blindness and tolerance. Even I know the names of these suicide bombers ... This is a scandal," Soli Ozel, a columnist and teacher at Kadir Has University, told Turkish news website Diken.
"In such a situation of course you would try to get away with saying Islamic State and the PKK did it together. Nobody in the world is taking this thesis seriously."
POLITICAL AGENDA
The authorities have not said why they believe the PKK or PYD, which is fighting Islamic State in Syria, would have been involved in the Ankara attack, which targeted a rally of pro-Kurdish activists and civic groups.
Senior officials have said DNA was found at the scene which linked some of those present to the PKK, although they acknowledge it is possible they may have been attending the rally rather than trying to attack it.
Turkey is fighting a renewed military campaign in its southeast against the PKK, which has waged a three-decade insurgency against the state to push for greater Kurdish autonomy and is classified as a terrorist organisation by the United States and European Union.
Ankara is meanwhile incensed by the role the PYD, which it accuses of deep links to the PKK, has carved out for itself, with the support of the United States, in the fight against Islamic State in northern Syria.
"The separatist terrorist organisation PKK is trying to deceive the international community and win legitimacy by operating under the name of PYD in Syria," Erdogan said in a second speech at his Ankara palace on Thursday.
In a phone call with Russian President Vladimir Putin on Wednesday, Erdogan underlined the importance of fighting "all terrorist groups in Syria" and again stressed the links between the PYD and PKK, sources in his office said.
"Part of the aim is to tarnish structures like the PYD in the eyes of the international community," said Meral Danis Bestas, a deputy head of the pro-Kurdish opposition Peoples' Democratic Party (HDP).