Turkey's government says it has bombed Islamic State (IS) targets in Syria.
A day earlier the two sides exchanged fire near the border, with one soldier killed and two more injured.
Turkey is to let the US carry out air strikes against the Islamic State group from a key military base near the Syrian border, US officials have said.
Turkish police also launched raids to arrest suspect IS militants on Friday morning in 140 locations in Istanbul.
The raids were carried out in 26 districts of the city and involved 5,000 officers. Members of the the youth wing of the outlawedKurdistan Workers' Party (PKK) and of a far-left group were also arrested.
The office of Turkey's Prime Minister, Ahmet Davutoglu, said members of militant groups were arrested in 13 provinces.
The state-run Anadolu news agency said some of the arrests were made in Ankara, Izmir and Sanliurfa province, near the Syrian border.
In a separate statement, Mr Davutoglu's office said that F-16 jets had hit three IS targets in Syria.
It is the first time Turkey has launched air raids against targets in Syria since IS began its advance through Iraq and Syria in 2013.
Turkish state TV said that the jets had not violated Syrian air space as they attacked the border town of Havar, next to the Turkish town of Kilis.
Turkey has seen a surge in IS-linked violence close to the Syrian border this week
The US is expected to step up bombing raids against IS after reaching an agreement with Turkey to use the Incirlik airbase.
The agreement was finalised in a phone call between President Barack Obama and his Turkish counterpart Recep Tayyip Erdogan on Wednesday. It was confirmed by US officials speaking on condition of anonymity.
The use of the Incirlik airbase broadens the US military's ability to strike IS targets - one US official told the New York Times it was a "game changer".
Once used in raids against former Iraqi leader Saddam Hussein, the base is near to Turkey's long border with Syria, and significantly narrows the distance to the IS stronghold of Raqqa.
A day earlier the two sides exchanged fire near the border, with one soldier killed and two more injured.
Turkey is to let the US carry out air strikes against the Islamic State group from a key military base near the Syrian border, US officials have said.
Turkish police also launched raids to arrest suspect IS militants on Friday morning in 140 locations in Istanbul.
The raids were carried out in 26 districts of the city and involved 5,000 officers. Members of the the youth wing of the outlawedKurdistan Workers' Party (PKK) and of a far-left group were also arrested.
The office of Turkey's Prime Minister, Ahmet Davutoglu, said members of militant groups were arrested in 13 provinces.
The state-run Anadolu news agency said some of the arrests were made in Ankara, Izmir and Sanliurfa province, near the Syrian border.
In a separate statement, Mr Davutoglu's office said that F-16 jets had hit three IS targets in Syria.
It is the first time Turkey has launched air raids against targets in Syria since IS began its advance through Iraq and Syria in 2013.
Turkish state TV said that the jets had not violated Syrian air space as they attacked the border town of Havar, next to the Turkish town of Kilis.
Turkey has seen a surge in IS-linked violence close to the Syrian border this week
The US is expected to step up bombing raids against IS after reaching an agreement with Turkey to use the Incirlik airbase.
The agreement was finalised in a phone call between President Barack Obama and his Turkish counterpart Recep Tayyip Erdogan on Wednesday. It was confirmed by US officials speaking on condition of anonymity.
The use of the Incirlik airbase broadens the US military's ability to strike IS targets - one US official told the New York Times it was a "game changer".
Once used in raids against former Iraqi leader Saddam Hussein, the base is near to Turkey's long border with Syria, and significantly narrows the distance to the IS stronghold of Raqqa.
[h=2]Analysis: Guney Yildiz, BBC News[/h]This agreement on Incirlik air base goes beyond providing the US-led coalition against IS with a geographical advantage.
Turkey has been in the coalition since from the beginning but was not fully cooperating due to its differing views over the Syrian crisis.
The Turkish government argued that the first priority of an international coalition should be removing President Assad rather than attacking IS. Having the Turkish government clearly backing the coalition brings extra political clout against IS.
The Turkish government, which has until the beginning of this year been accused of turning a blind eye by allowing IS fighters to cross its borders, was under huge international pressure to open the airbase.
The negotiations between the US and the Turkish government came to fruition as recent attacks by IS against Turkish and Kurdish targets added an urgency to the response.
Turkey has been in the coalition since from the beginning but was not fully cooperating due to its differing views over the Syrian crisis.
The Turkish government argued that the first priority of an international coalition should be removing President Assad rather than attacking IS. Having the Turkish government clearly backing the coalition brings extra political clout against IS.
The Turkish government, which has until the beginning of this year been accused of turning a blind eye by allowing IS fighters to cross its borders, was under huge international pressure to open the airbase.
The negotiations between the US and the Turkish government came to fruition as recent attacks by IS against Turkish and Kurdish targets added an urgency to the response.
The deal marks a step up in Turkey's involvement in the campaign against IS.
The Turkish government has faced criticism at home and abroad for not doing enough against the extremist group, despite being part of the international coalition fighting IS.
Protests against the attack in Suruc have taken place in cities across TurkeyT
hursday saw a deadly exchange of fire between Islamic State and Turkey near Kilis.
IS fighters attacked a Turkish border post, with Turkey's army retaliating with heavy weaponry, killing one of the militants.
The incident comes days after the deadly bombing in the predominantly Kurdish town of Suruc, in which 32 people were killed, mostly university students.
The Turkish authorities blamed the attack on IS, with the bomber identified as a 20-year-old believed to have travelled to Syria last year with the help of an IS-linked group.
Kurdish militants said they killed two police officers in the city of Celanpinar as retaliation, accusing the policemen of having collaborated with IS.
Turkey would take "all necessary measures" to protect national security following the attacks, the prime minister's office said.
The Turkish government has faced criticism at home and abroad for not doing enough against the extremist group, despite being part of the international coalition fighting IS.
Protests against the attack in Suruc have taken place in cities across TurkeyT
hursday saw a deadly exchange of fire between Islamic State and Turkey near Kilis.
IS fighters attacked a Turkish border post, with Turkey's army retaliating with heavy weaponry, killing one of the militants.
The incident comes days after the deadly bombing in the predominantly Kurdish town of Suruc, in which 32 people were killed, mostly university students.
The Turkish authorities blamed the attack on IS, with the bomber identified as a 20-year-old believed to have travelled to Syria last year with the help of an IS-linked group.
Kurdish militants said they killed two police officers in the city of Celanpinar as retaliation, accusing the policemen of having collaborated with IS.
Turkey would take "all necessary measures" to protect national security following the attacks, the prime minister's office said.
