Turkey on Friday detained 251 people in coordinated nationwide dawn raids against suspected Islamic State (IS) jihadists and Kurdish militants following a wave of deadly violence in the country, the prime minister's office said.
"A total of 251 people were taken into detention for belonging to terrorist groups," the statement said, adding that the raids took place in 13 provinces across Turkey.
It said that the arrests had been made following violent attacks against members of the public and the armed forces in recent days.
Reports said police raided addresses in several Istanbul districts in search of members of IS, the Kurdistan Workers Party (PKK) and other militant groups.
The Dogan news agency said that 140 addresses were raided in 26 districts in Istanbul alone, in a giant operation involving some 5,000 police.
As well as IS and the PKK, the operation targeted suspected members of the PKK's youth wing the The Patriotic Revolutionary Youth Movement (YDG-H) and the Marxist Revolutionary People's Liberation Party Front (DHKP-C), the state Anatolia agency said.
The raids came after 32 people were killed in a suicide bombing Monday in a Turkish town on the Syrian border, blamed on IS.
This sparked an upsurge in violence in Turkey's Kurdish-dominated southeast, where many accuse the Turkish authorities of collaborating with IS, accusations Ankara denies.
Two police were shot dead in southeast Turkey close to the Syrian border on Wednesday, in an attack claimed by the PKK's military wing which said it wanted to avenge the Suruc bombing.
On Thursday, another policeman was killed in the majority Kurdish city of Diyarbakir.
Meanwhile, YDG-H claimed it had shot dead an alleged former IS fighter in Istanbul late Tuesday.