Turkish authorities have identified one of two suicide bombers who killed 102 people in Ankara this month as a young man from southeast Turkey whose brother carried out a similar attack in July.
The brothers were known in their hometown for trying to recruit fighters for Islamic State.
On October 19, the Ankara prosecutor's office named the Ankara bomber as Yunus Emre Alagoz from the town of Adiyaman and said work was continuing on identifying the other bomber through DNA tests.
Alagoz's bombing targeted pro-Kurdish activists in the worst attack of its kind in modern Turkey's history.
His brother Seyh Abdurrahman Alagoz walked into a group of pro-Kurdish student activists in Suruc near the Syrian border in July and blew himself up, killing 33 people.
Prime Minister Ahmet Davutoglu told AHaber TV that 15 people have been detained over the bombing, four of whom were remanded in custody.
They also said their search had turned up a large cache of suicide vests, Kalashnikov rifles, hand grenades, and hundreds of kilograms of explosives.