Turkey has deported some of the eight suspected members of the Islamic State group who were detained in Istanbul this week, but others are still in custody, a government official said on Thursday.

Counter-terror police detained the suspects at Istanbul's Ataturk Airport after they flew in from the Moroccan city of Casablanca on Tuesday.

Turkish police detained eight suspected members of the Islamic State jihadist (IS) group, state media said Wednesday, adding they were planning to sneak into Europe posing as refugees.

Counter-terror police detained the suspects in Istanbul's Ataturk Airport after they flew in from the Moroccan city of Casablanca on Tuesday, the official Anatolia news agency reported.

Turkey's foreign minister on Wednesday said Ankara "has plans" for a joint operation with the United States to end the presence of Islamic State militants along any part of its border with Syria.

Foreign Minister Feridun Sinirlioglu told the state-run news agency Anatolia that IS militants still had a presence on some of Turkey's border with northern Syria.

Greek Prime Minister Alexis Tsipras held talks Wednesday with the Greek orthodox patriarch as he embarked on his first official visit to Turkey set to be devoted to grappling with the huge flow of refugees entering his country from Turkish territory.

Tsipras, who arrived in Turkey late Tuesday, held a 40-minute meeting with the Istanbul-based Ecumenical Patriarch Bartholomew I, the spiritual leader of the world's Orthodox Christians.

A Syrian journalist who lives and works in the war-scarred city of Aleppo was awarded the Reporters without Borders Prize in France on Tuesday for her defense of press freedom.

The Paris-based media rights group singled out Zaina Erhaim for her "determination and courage" in covering the conflict in Syria, which is deemed the most dangerous country in the world for journalists.

Turkey warned France almost a year ago over a suspected Islamic State group jihadist who blew himself up in the Paris attacks but the French authorities did not respond, a senior Turkish official said on Monday.

Turkish police "notified their French counterparts twice -– in December 2014 and June 2015" about Omar Ismail Mostefai, the official told AFP, asking not to be named.

Turkey's election board on Thursday confirmed the landslide win for President Recep Tayyip Erdogan's Justice and Development Party (AKP) in the November 1 election.

The AKP secured 317 seats in the 550-member parliament, winning back the majority it lost in a June election in defiance of opinion polls that had predicted another hung parliament.

Turkish police have stormed the offices of a leading opposition paper linked to President Recep Tayyip Erdogan's arch foe, in the latest crackdown on government rivals.

As riot police armed with water cannon massed outside, officers and lawyers searched the Istanbul offices of the Zaman newspaper late Wednesday, the paper said.

Turkish President Recep Tayyip Erdogan on Wednesday called on world leaders to rally behind Turkey's plan for a safe zone inside Syrian territory, days before it hosts the G20 summit.

Speaking to a group of businessmen in the capital Ankara, Erdogan said the Syrian conflict would be a "major topic" at the G20 summit in the Mediterranean resort of Antalya on Sunday and Monday.

Turkey on Tuesday rejected as "unfair" a European Union report criticizing the state of the rule of law, human rights and media freedom in the EU candidate country.

Some of the report's observations are "unfair and even partly disproportionate, and ignore the freedom-security balance required in a democratic country governed by the rule of law", the ministry responsible for EU affairs said in a statement.