has not claimed responsibility for the carnage, which struck during a peace rally.
The terror group has also not claimed responsibility for a suicide bombing in the town of Suruc
near the Syrian border in July that killed 34 people.
Using the Arabic acronym for ISIS, Daesh, Davutoglu told Turkish television NTV, "We investigate Daesh as our No. 1 priority. There (has) been good progress toward identifying a name. That name points to an organization."
Davutoglu also said the Kurdish PKK and the leftist DHKP-C could be behind the two suicide bombers who detonated their explosives near the city's main train station.
Here's a little more about those two less globally known groups.
The PKK is the Kurdistan Workers' Party
, a militant group that has waged a separatist campaign for more than 30 years.
It would have been a brutally cynical act for the PKK to attack a peace rally attended by Kurds. Most of the victims of Friday's bombings were attending a lunchtime demonstration calling for an end to the renewed conflict between the PKK and the Turkish government. Those taking part included the pro-Kurdish HDP, or Peoples' Democratic Party, which said on Twitter two of its parliamentary candidates were killed in the blasts.
Davutoglu has said recently that would-be suicide bombers have been arrested crossing into Turkey from Iraq, where the PKK has bases. ISIS does not control any part of Iraq's border with Turkey, though it does have access to parts of Syria's border with Turkey.
The Turkish military has conducted airstrikes
in recent months against suspected PKK targets in the mountains of northern Iraq.
Kurdish forces have been battling ISIS jihadists across a swath of northern Iraq and Turkey.
The Revolutionary People's Liberation Party-Front is a far-left group that claimed responsibility for a 2013 suicide bombing at the U.S. Embassy in Ankara. This summer the group said it had attacked the U.S. Consulate
in the city of Istanbul.
The group was first formed in 1978 under the name Revolutionary Left. Though it has had many incarnations over the years, according to IHS Jane's world security analysis, the group describes itself as Marxist-Leninist, internationalist and anti-imperialist.
Its primary stated objective is the establishment of a Marxist-Leninist state in Turkey, Jane's reports. It has attacked Western political and economic targets, particularly U.S. and UK interests.
In the Suruc attack in July, an explosion at midday injured at least 100 and killed scores at the Amara Cultural Park, where a group had gathered to call for more help to rebuild the Syrian Kurdish city of Kobani, CNN Turk reported. Suruc is about 6 miles from the border and Kobani, the Syrian city that was the scene of intense fighting between Syrian rebels and Kurdish forces and ISIS.