The Turkish authorities have identified a man as one of the two suspected perpetrators of the twin suicide bombing in Ankara on Saturday, the Bulgarian National Radio (BNR) reported on Sunday.

The 25-year old man was allegedly a brother of the suicide bomber who carried out an attack in the town of Suruc in July that killed 32 people and left hundreds injured. The Ankara bomber was reportedly a member of the Islamic State group, BNR said.

The identity of the second Ankara bomber, who might have been a female, hasn’t been established yet.

Turkish authorities on Sunday released the names of 77 victims whose identity has been established. None of them is a Bulgarian national, BNR said.

Turkish Prime Minister Ahmet Davutoglu said earlier that Islamic State jihadists, Kurdish hard-line militants or extreme-left radicals could have carried out the bombing, the deadliest of its kind in Turkey, international newswires reported.

Militant nationalists opposed to any settlement with Kurds seeking greater minority rights could also have been responsible, according to other suggestions.

There have been no claims of responsibility for the twin blast that hit a rally of pro-Kurdish and labour activists near Ankara’s main train station three weeks before parliamentary elections.