ANKARA • Turkey and the United States have agreed to clear northern Syria of Islamic State in Iraq and Syria (ISIS) militants to create "safe regions" for displaced Syrians, Turkish Foreign Minister Mevlut Cavusoglu said yesterday.

"Syrian refugees in Turkey and in neighbouring countries will be able to settle in these safe regions," Mr Cavusoglu said, adding that Ankara has also given the green light to US forces using Turkey's Incirlik base for air strikes against ISIS in Syria and Iraq.

In the long term, Turkey plans to keep Syrian refugees in this zone rather than give them shelter in Turkish territory. Mr Cavusoglu said the zone would give Syrian refugees - 1.8 million of whom are in Turkey - a chance to "return to their homeland".

The local Hurriyet Daily News reported that members of the Free Syrian Army, a rebel group, could also be deployed in the ISIS-free zone, which will be 98km long and 40km wide.

The agreement came as Turkey's military carried out second and third waves of air strikes against ISIS militants in Syria and Kurdish militants in northern Iraq in an escalating campaign that Ankara says is aimed at rooting out terror. At the same time, Turkish ground forces used artillery to pound targets belonging to both groups.

The two-pronged operation against ISIS and the outlawed Kurdistan Workers Party (PKK) - two groups which are themselves bitterly opposed to each other - came after a week of deadly violence in Turkey which the authorities blamed on both organisations.

"No one should doubt our determination," Prime Minister Ahmet Davutoglu said. "We will not allow Turkey to be turned into a lawless country. These operations are not 'one-point operations' and will continue as long as there is a threat against Turkey."

The raids against ISIS in Syria, which began before dawn on Friday, marked a major shift in policy towards the group by Turkey, a key Nato member which has faced severe criticism from its Western allies for not doing enough to combat the militants.

Turkey's change of heart came after a cross-border gunfight between suspected ISIS militants in Syria and troops in Turkey left one of its soldiers dead on Thursday, just days after a suicide bombing also blamed on ISIS killed 32 people in the town of Suruc.

But the "anti-terror" operation has been expanded to include strikes on the PKK in neighbouring Iraq, where the banned group's military forces are based.

The PKK slammed the air raids on its northern Iraq mountain stronghold, saying a fragile ceasefire that had been in place since 2013 with Turkey "no longer has any meaning".

Mr Davutoglu said he spoke yesterday with Mr Massud Barzani, the president of the Kurdish-ruled autonomous region in northern Iraq, who had expressed "solidarity" with the operation against the PKK.

Turkish security forces yesterday also launched raids to arrest suspected ISIS and PKK members in Istanbul and other cities, adding to hundreds of detentions made the day earlier.

A total of 590 people have so far been arrested across Turkey for suspected links to terror groups and for allegedly posing a threat to the state, Mr Davutoglu said.

With tensions running high across the country, Turkish police late on Friday used tear gas and rubber bullets to disperse hundreds of protesters in the Kadikoy district of Istanbul who had gathered to denounce ISIS violence.

Protesters in the anti-establishment district of Gazi also defiantly carried the coffin of Ms Gunay Ozarslan, a female activist killed in clashes with police on Friday during a raid on leftist militants, according to an Agence France- Presse photographer.

XINHUA, AGENCE FRANCE-PRESSE, REUTERS