The killings shook a country already traumatized by nearly a year and a half of attacks on civilians, renewed fighting with Kurdish militants, and a failed military coup attempt that left at least 265 people dead in July.
The attacks also illustrate the security challenges facing the government of President Recep Tayyip Erdogan, a polarizing leader who emerged stronger from the July coup attempt and has moved to clamp down on political opponents in recent months.
A Kurdish militant group known as the Kurdistan Freedom Falcons claimed responsibility for the attack on Sunday. The organization the group is regarded a splinter faction of the dominant Kurdish separatist group, the Kurdistan Workers’ Party (PKK). Earlier on Sunday, Turkey’s deputy prime minister, Numan Kurtulmus, said an initial investigation suggested that the PKK itself was behind the attack. The organization and splinter groups have primarily attacked security forces in the past. Civilians have also died in some attacks blamed on the group.