Four suspects were arrested in Turkey late on Wednesday in connection with car bombings that killed 51 people in a town near the Syrian border at the weekend, state-run Anatolian news agency reported.
The two bomb blasts in Reyhanli fanned fears that Syria’s civil war is dragging in neighboring states. Damascus has denied Turkish allegations it was involved in the blasts.
Turkish prosecutors sent eight suspects to a court in the southern city of Adana after questioning and the court released four, remanding the other four in custody, the agency said.
It was not clear what charges they were facing.
A total of 17 people have been detained in connection with the attacks and police were continuing to question the remaining suspects.
The arrests were made after Syria states its willingness to carry out a joint investigation with Turkey.
“If the government of [Prime Minister Recep Tayyip] Erdogan calls for a joint, transparent investigation by the two countries, we have no objection, in order to find the truth,” Syrian Information Minister Omran al-Zohbi said on Tuesday.
“The truth must be announced to the Syrian and Turkish people,” official media quoted him as saying.
His offer was firmly refused by Turkish Prime Minister Recep Tayyip Erdogan later on Tuesday.
“The administration in power in Damascus is illegal ... how can we recognize a structure that isn’t even recognized by its own citizens,” Erdogan told reporters before leaving for a meeting with U.S President Barack Obama in Washington on Thursday.
Ankara has sided with the rebels fighting to topple Assad’s regime and has taken in around 400,000 refugees as well as army defectors and repeatedly called on the international community to act on the unfolding crisis.