Turkey says eight IS suspects posed as refugees

The International Organisation for Migration and the UNHCR also report that, to date, there has not been a single proven case of terrorists infiltrating migrant flows to Europe

But the announcement from Ankara is likely to stoke fears among some member states, which oppose EU asylum relocation plans.

The Islamic State itself is also said to want Western leaders to link terrorism with refugees to stem the flow to the EU because the Syrian exodus is seen as undermining its so-called caliphate.

Both Hungary and Slovakia are now seeking to challenge the EU relocation plan at the European Court of Justice in Luxembourg.

Meanwhile, Amnesty International, in a report out earlier this week, described cases of people fleeing war being turned around in Greece and Bulgaria and sent back into Turkey in contravention to EU and international laws.

The human rights organisation also said Turkey is “detaining intercepted migrants and asylum-seekers without access to lawyers and forcibly returning refugees to Syria and Iraq, in clear violation of international law”.

But the EU, for its part, is pushing ahead with plans to finalise a migrant deal with Turkey in exchange for money, visa liberalisation, and accelerated talks on EU membership.

The EU agreed early October to an EU-Turkey joint action plan but still needs to shore up some €3 billion.

In an interview with Reuters, EU enlargement commissioner Johannes Hahn said the EU wants “a fresh start in our relationship with Turkey."

Hahn was speaking of an upcoming EU-Turkey summit. The plan is to give Turkey €3 billion to contain the some 2.2 million Syrian refugees it hosts.

"Such a summit is a good opportunity to announce a deal. I still expect this before Christmas," he said.

In related developments, Greece and Turkey on Wednesday announced they would set up new posts in their respective embassies to host coast guard attaches.

Some 690,000 people have entered Greece to seek international protection since the start of the year.

The vast majority take a boat from Turkey to reach the nearby Greek islands in the Aegean sea.

Turkey’s prime minister Ahmet Davutoglu, speaking alongside his Greek counterpart Alexis Tsipras, said any solution to the refugee crisis must be found in Syria.

Davutoglu also noted that greater efforts would be made to reunify Cyprus.

The island-nation has been split in two since Turkey’s 1974 invasion.

“There is a window of opportunity right now over the Cyprus issue. The negotiations are going on. We have a common approach with Greece to contribute positively to the talks,” said Davutoglu.