A car bomb has killed 13 soldiers and wounded 56 after it ripped through a bus carrying off-duty military personnel in the central Turkish city of Kayseri in an attack President Tayyip Erdogan is blaming on Kurdish militants.
The blast on Saturday, a week after deadly twin bombings targeted police in Istanbul, is likely to further outrage a public smarting from a series of attacks this year - several claimed by Kurdish militants, others by Islamic State - and a failed coup in July.
It could also increase tension in the mainly Kurdish southeast, where militants from the Kurdistan Workers Party (PKK) have waged a three-decade violent insurgency that has seen some of the worst fighting in the last year.
"The style and goals of the attacks clearly show the aim of the separatist terrorist organisation is to trip up Turkey, cut its strength and have it focus its energy and forces elsewhere," Mr Erdogan said in a statement.
"We know that these attacks we are being subjected to are not independent from the developments in our region, especially in Iraq and Syria."
Mr Erdogan frequently refers to the PKK as "the separatist terrorist organisation". The PKK, which wants autonomy for the Kurdish minority, is considered a terrorist group by the United States, the European Union and Turkey.
Turkey, a NATO member and part of the US coalition against Islamic State, has also been angered by Washington's backing of Syrian Kurdish fighters against the Sunni hardline group.
Turkish authorities have so far detained seven people and are searching for another five in relation to the car bomb, Interior Minister Suleyman Soylu said.
Health minister Recep Akdag told the news conference that a large number of the wounded were lightly injured.
Mr Erdogan confirmed that 13 people had been killed and 56 wounded in Saturday's blast.
All of those killed and 48 of the wounded were off-duty military personnel, the military said. The bus was mainly carrying privates and corporals, it said.
There was no immediate claim of responsibility, but government officials likened the attack to last Saturday's dual bombings outside the stadium of Istanbul soccer team Besiktas, later claimed by a PKK offshoot.
Later on Saturday, a crowd stormed the local headquarters of the pro-Kurdish Peoples' Democratic Party (HDP), parliament's second-largest opposition party. The office was vandalised and some documents set on fire, a party spokesman said.
The HDP condemned the bus bombing and called for an end to politics and language that creates polarisation, hostility and violence.