Turkey's air force has attacked Islamic State (IS) positions in Syria and Kurdish PKK militants in northern Iraq to defend the country's security, Turkish PM Ahmet Davutoglu says.
Mr Davutoglu added that 590 suspected IS and PKK members had been arrested.
This follows a week which saw a bomb attack blamed on IS kill 32 people in the Turkish town of Suruc.
Subsequent clashes with IS fighters on the Turkey-Syria border led to the death of a Turkish soldier.
The PKK's military wing said it had killed two Turkish police officers on Wednesday, claiming they had collaborated with IS in the bombing in Suruc, which targeted left-wing activists.
US White House spokesman Alistair Baskey said Turkey had the right to defend itself against terrorist attacks by Kurdish rebels and urged the PKK to renounce terrorism.
But he said that Ankara should also avoid violence towards the PKK and seek to de-escalate the conflict.
Analysis: Mark Lowen, BBC Turkey correspondent
Within a week, Turkey has gone from reluctant observer of the coalition against IS to military strikes, opening up its bases to warplanes and bombing of PKK positions. What changed?
Partly it's months of negotiations between Washington and Ankara. General John Allen, the US envoy for the anti-IS coalition, has paid several visits here to twist arms. The Turkish government pushed for a no-fly area to be implemented inside Syria. It appears Washington gave some ground, accepting a "buffer zone" to clear IS militants from close to the Turkish border, patrolled by US and Turkish warplanes.
The suicide bomb last week in Suruc, which killed 32 people and was blamed on IS, was a catalyst.
But it seems Turkey insisted that strikes against IS go hand-in-hand with those against the PKK. That complicates matters: the coalition is working with Kurdish forces against IS and a fragile ceasefire with the PKK may now end, raising fears of renewed Kurdish violence in Turkey. President Recep Tayyip Erdogan has one eye on possible new elections in the autumn, hoping to court nationalist voters. A hard line against the PKK would help that.
A government statement on Saturday morning said the air force had hit PKK shelters, bunkers, storage facilities and other "logistic points" in northern Iraq, including the Qandil mountains where the PKK's high command is based.
It did not give details of what the jets had targeted in their attacks on IS in Syria.
Turkey's military had also shelled Islamic State and PKK positions from across the Turkish border, the statement said.
Speaking to reporters on Saturday, Prime Minister Davutoglu said: "Unfortunately Turkey is surrounded by a ring of fire.
"In such an atmosphere, Turkey tries to keep her democracy and development alive... these operations have carried a message to the countries in the region and to international circles: whatever happens in Syria and Iraq, in our border regions, we will not allow them to threaten Turkey's security and will not hesitate to take necessary measures."
Turkish Foreign Minister Mevlut Cavusoglu said areas of northern Syria cleared of IS fighters would become natural "safe zones".
Turkey has also said it will let the US use a key airbase to attack IS targets.
Separately the Turkish authorities have banned a peace march due to take place in Istanbul on Sunday, expressing concern about possible "provocative action" and "dense traffic".
'Truce has no meaning'
The overnight air strikes in northern Iraq were the first time Turkey had attacked the PKK (Kurdistan Workers' Party) since a 2013 truce.
The group has been fighting Turkey for an autonomous homeland for the Kurds for decades.
In a statement on its website quoted by Reuters news agency, the PKK said: "The truce has no meaning any more after these intense air strikes by the occupant Turkish army."
The Turkish government has faced criticism at home and abroad for not doing enough against IS, despite being part of the international coalition fighting it.
The first round of anti-IS air strikes on Friday marked the first time Turkey had confirmed air strikes against targets in Syria since IS began its advance through Iraq and Syria in 2013.
The agreement to let the US use the Incirlik airbase, following months of negotiations, was made in a phone call between President Barack Obama and Turkish President Recep Tayyip Erdogan - but has yet to be approved by the Turkish cabinet.
It could allow the US to step up air strikes against IS, as it is closer to northern Syria and Iraq than the Gulf, which currently serves as a launch-pad for bombing missions.
A return to Incirlik
The US military is more than familiar with the southern Turkish base, and its recent history is tied closely with recent US military operations.
- During the first war against Iraq in 1990, US planes were stationed at the base
- Humanitarian operations for Kurdish refugees flew out of Incirlik after the war
- The base also served as the main hub for operations at the start of the war in Afghanistan in 2001
- It acted as the first stop on the way home for thousands of US troops leaving Iraq after the 2003 invasion
- Wikileaks claimed the US and Turkey allowed the base to be used to launch rendition flights for terror suspects
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