Humeyra Pamuk and Jonny Hogg ISTANBUL/ANKARA — Defne Bayrak's husband was a suicide bomber who killed CIA operatives in a 2009 attack in Afghanistan. Now, she is among the hundreds of Turks using social media to show support for the Daesh (the so-called IS) militants in Syria and Iraq. Turkey, a Sunni Muslim nation with a secular constitution, is a member, albeit reluctantly, of the US-led coalition against Daesh. Most of its 77 million people are deeply opposed to the militant group's savage tactics. But pockets of Turkish social media hum with pro-Islamic State activity and at least six websites provide daily updates on its self-declared caliphate, carved out in Syria and Iraq. An October survey by pollster Metropoll said up to 12 percent of Turks do not see the group as a "terrorist organization". This sympathy is of growing concern to officials in Ankara, diplomats and security experts say, as they fear a network of fighters, recruiters and facilitators is being cultivated in Turkey to support Daesh operations over the border. Turkey has stepped up its efforts to destroy these networks but analysts say pushing the militants too far could lead to the EU candidate nation becoming a target itself, particularly ahead of June elections. "From the beginning Turkey didn't fully appreciate the danger of the Daesh networks. Now it has become riskier to dismantle them," said Bahadir Dincer, Middle East Expert at the Ankara-based think-tank USAK. "A Daesh attack is the number one threat for Turkey at the moment ... This is a huge risk for the government before the elections." Bayrak, her Twitter page emblazoned with the Daesh logo and pictures of the group's fighters riding on pick-up trucks, tweeted last week that she had "migrated to the land of the caliph". "People said it accused people of being infidels, hanged and killed people. I have seen no such thing since my arrival," she said in one tweet. "My God would grant their successors the conquest of Rome," she said in another. Foreign Minister Mevlut Cavusoglu has estimated that the number of Turks who have joined Daesh is around 500-700, lower than from some European countries, although some diplomats put the number of Turks in the thousands. US officials have estimated that as many as 15,000 foreign fighters are operating in Syria alone, including 3,000 Westerners, many of whom crossed through Turkey. The Turkish authorities say they have blocked entry to Turkey to more than 7,000 would-be militants in recent years. But the crackdown, carried out under pressure from concerned European partners, has ratcheted up the risk that Turkey itself becomes a target for returning militants. Halis Bayancuk, a Turkish cleric detained several times on suspicion of aiding Al-Qaeda, cautioned Ankara against taking a more active role in the US-led fight against Daesh. "I believe Turkey could be harmed because of it," Bayancuk, also known as ‘Abu Hanzala', said in an apartment-turned-prayer room on a run-down street in Istanbul's Gunesli neighborhood. "I wouldn't know what kind of harm. But if you team up with the West in their war ... you'd lose all legitimacy in the eyes of the people of the Middle East." — Reuters