Separatist group the Kurdistan Freedom Hawks has claimed responsibility for a bomb attack on a military bus that killed five people in Istanbul on Tuesday.
The group is believed to have links with the main Kurdish separatist group the PKK.
The roadside attack was the worst to hit Istanbul in two years and comes as Prime Minister Recep Tayyip Erdogan is under increasing criticism for his reformist approach to the Kurdish question.
“In the fight against terrorism, we will do everything,” he told parliament in the wake of the attack. “We will make up any shortfalls. We will continue to battle strongly and decisively.”
But he rejected calls from nationalist politicians for a return to emergency rule in the southeast.
Erdogan has granted more political and cultural rights to Kurds in an attempt to diffuse the conflict.
But fighting with the PKK has claimed the lives of more than 50 soldiers over the last two months, including eleven at the weekend and conservatives accuse him of showing weakness in the face of PKK violence.