Turkey's prime minister says authorities have confirmed the identity of one of the two suicide bombers they say targeted a peace rally in the capital Ankara, killing 102 people.

In an interview with A Haber television Monday, Ahmet Davutoglu said officials were still trying to confirm the identity of the second bomber.

Davutoglu said Turkish authorities have formally arrested four people in connection with the attacks. Eleven other people who were also detained for questioning have been released but four of them could still face charges.

He did not provide further details.

The Oct. 10 attacks outside city's main train station were Turkey's deadliest.

Unconfirmed reports have said the attacks were carried out by a Turkish cell of the Islamic State group, also blamed for a similar attack in July.