Though no group has claimed responsibility for the deadly weekend bombings in Ankara, the focus of the investigation is the Islamic extremist group ISIS, Turkey ' s Prime Minister said Monday. Two suicide bombers are believed to have carried out Saturday's attack near Ankara's main train station, killing at least 97 people and wounding nearly 250 others, Turkey has said. Authorities have begun to collect DNA samples from relatives of those suspected of having joined ISIS to help identify possible suspects in the bombings, Turkey's semiofficial Anadolu news agency reported. Not specifically identifying any group behind the act, Prime Minister Ahmet Davutoglu told Turkish television station NTV on Monday, "We investigate Daesh (ISIS) as our No. 1 priority. There (has) been good progress toward identifying a name. That name points to an organization." Davutoglu said his country had come face to face with suicide bombers a long time ago. "This attack will not turn Turkey into a Syria," he said. The weekend blasts targeted crowds at a lunchtime peace rally calling for an end to the renewed conflict between the Kurdistan Workers' Party, or PKK, and the Turkish government. Kurdish forces have been battling ISIS jihadists across a swath of northern Iraq and Syria, and the Turkish government recently changed its stance to allow the United States to launch strikes on the militant group's positions from Incirlik Air Base in southern Turkey.