Turkey's outgoing premier Recep Tayyip Erdogan was Thursday sworn in as president to extend his decade-long rule, as opponents who accuse him of authoritarianism walked out of the ceremony.

Erdogan, 60, took the oath in Ankara to begin a five-year mandate in which he has vowed to build a "new Turkey" by pushing through a new constitution and driving on with an ambitious development program.

Turkey's ruling party on Thursday confirmed Foreign Minister Ahmet Davutoglu as the successor to Recep Tayyip Erdogan as premier and party leader, with both men vowing the handover would herald no change in strategy.

Erdogan, 60, is to be sworn in as president on Thursday and the approval of Davutoglu, 55, from the ruling Justice and Development Party (AKP) was a key step in a tightly-choreographed succession process.

Foreign Minister Ahmet Davutoglu, Turkey's next prime minister, is a loyal ally of incoming president Recep Tayyip Erdogan and the chief architect of an assertive but increasingly controversial foreign policy.

Davutoglu was approved on Wednesday by the ruling Justice and Development Party (AKP) as its new leader and prime minister to take over when Erdogan moves to the presidency on Thursday.

Thousands of people on Tuesday came together in Ankara to form the world's largest portrait of Mustafa Kemal Ataturk, the founder of the modern Turkish republic who remains its number one national hero.

At least 6,000 volunteers gathered outside the Anitkabir mausoleum, Ataturk's final resting place, to form the larger-than-life portrait for an event marking Turkey's Victory Day.

Turkey's new premier and outgoing foreign minister Ahmet Davutoglu leaves his successor a troubled legacy after a bold policy to expand Turkish influence across the ex-Ottoman empire left the country painfully exposed to the Syria and Iraq crises.

Kurdish militants abducted three Chinese workers in Turkey's southeast after the rebels attacked the thermal energy plant where they work, state media said Monday.

Militants from the Kurdistan Workers' Party (PKK) kidnapped the Chinese workers late Sunday while they were doing grocery shopping near the Iraiq border, the Anatolia news agency said.

Hundreds of Istanbul residents angered by the presence of Syrian refugees clashed with police early Monday in a violent protest in a suburb of Turkey's biggest city, reports said.

The clashes were the latest violence amid growing tensions between Turkish locals and Syrian refugees who fled the civil war in their country and whose numbers in Turkey have now swelled to 1.2 million.

Families who once fled a Turkish crackdown on Kurdish rebels in the 1990s now languish in a mosque in northern Iraq after escaping from brutal jihadists, longing to return home.

They lived as refugees in Makhmur, a town in northern Iraq, until the Islamic State (IS) jihadist group, which spearheaded a militant offensive that has overrun large areas of Iraq, forced them to leave.

Turkey and Qatar have kicked off efforts to negotiate the release of the soldiers and security forces abducted from Arsal following the clashes in the northeastern town, reported As Safir newspaper on Saturday.

Diplomatic sources told the daily that the initiative is being held in coordination with Prime Minister Tammam Salam and Mustaqbal Movement chief MP Saad Hariri.

The Muslim Scholars Committee delegation announced on Friday that it was suspending its mediation regarding the release of the soldiers and security forces abducted from the northeastern border town of Arsal.

It explained that it took its decision pending better circumstances in the mediation.