ANKARA, Turkey — Turkey’s prime minister vowed Sunday his country will not be drawn into Syria’s civil war, despite twin car bombings the government believes were carried out by a group of Turks with close ties to pro-government groups in Syria.
The bombings left 46 people dead and marked the biggest incident of violence across the border since the start of Syria’s bloody civil war, raising fears of Turkey being pulled deeper into a conflict that threatens to destabilize the region.
Syria has rejected charges it was behind the attacks. But Turkish authorities said Sunday they had detained nine Turkish citizens with links to the Syrian intelligence agency in the bombings in the border town of Reyhanli, a hub for Syrian refugees and rebels just across from Syria’s Idlib province.
Harsh accusations have flown between Turkey and Syria, signaling an escalation of already high tensions between former allies. But Prime Minister Recep Tayyip Erdogan indicated Turkey would not be drawn militarily in retaliation.
He insisted Turkey would ‘‘maintain our extreme cool-headedness in the face of efforts and provocations to drag us into the bloody quagmire.’’
‘‘Those who target Turkey will be held to account sooner or later,’’ he said. ‘‘Great states retaliate more powerfully, but when the time is right. . . . We are taking our steps in a cool-headed manner.’’
Turkish Foreign Minister Ahmet Davutoglu told reporters in Berlin those detained were linked to a Marxist terrorist group.
Sabah, a Turkish newspaper close to the government, reported Sunday that authorities suspect the leader of a former Marxist group, Mirhac Ural, now thought to be based in Syria, may have revived his group and ordered the attack.
The group, Acilciler, was one of many Marxist groups active in Turkey in the 1970s and 1980s, and was long-rumored to have been formed by the Syrian intelligence agency. Many of its militants allegedly included ethnic Arab Turks belonging to a sect close to Syria’s Alawites.
‘‘Some believe that now that relations [with Turkey] have deteriorated again, Syria may have reactivated the group to cause turmoil in Turkey,’’ said Nihat Ali Ozcan, a terrorism expert at the Economic Policy Research Foundation of Turkey.
Authorities said a ringleader was among those detained, and more arrests were expected.
The twin bombings 15 minutes apart Saturday damaged about 735 businesses and 120 apartments, leaving smoking hulks of buildings and charred cars. It also wounded dozens of people, including 50 who remained hospitalized Sunday.
Syria and Turkey became adversaries early in the uprising against Syrian President Bashar Assad that erupted in March 2011. Since then, Turkey has sided with the Syrian opposition, hosting its leaders along with rebel commanders and providing refuge to hundreds of thousands of Syrian refugees.