Turkey believes fighters loyal to Syrian President Bashar al Assad were behind two car bombings that killed 46 people in a Turkish border town where thousands of Syrian refugees live.

Authorities have arrested nine people, all Turkish citizens and including the alleged mastermind, after the bombings in Reyhanli on Saturday, according to Deputy Prime Minister Besir Atalay.

Foreign Minister Ahmet Davutoglu said those involved were thought also to have staged an attack on the Syrian coastal town of Banias a week ago in which at least 62 people were killed.

The car bombs increased fears that Syria's civil war is dragging in neighbouring states, despite renewed diplomatic moves towards ending two years of fighting in which more than 70,000 people have been killed.

"The attack has nothing to do with the Syrian refugees in Turkey, it's got everything to do with the Syrian regime," Mr Davutoglu said in a television interview.

"We should be careful against ethnic provocations in Turkey and Lebanon after the Banias massacre."

Syrian Information Minister Omran Zubi denied any Syrian involvement.

The conflict has inflamed a confrontation between Sunni and Shi'ite Muslims in the Middle East, with Shi'ite Iran supporting Mr Assad, and Sunni powers like Saudi Arabia backing the rebels.

l Syrian rebels have freed four Filipino UN peacekeepers captured last week on the ceasefire line between Syria and the Israeli-occupied Golan Heights.

The rebels from the Yarmouk Martyrs' Brigade had said they were holding the soldiers for their own safety after clashes with Syrian Government forces had put them in danger.