On Saturday, Turkey risked double-fronted warfare against "Islamic State" (IS) and Kurdish forces in Syria and Iraq, respectively. IS and the Kurdistan Workers' Party (PKK) are themselves bitter foes. Ankara's change of tack follows a suicide bombing last Monday that shook Turkish society.

At midday on Saturday, Prime Minister Ahmet Davutoglu told reporters in Ankara that a third wave of "air and ground operations" had begun against both the IS and PKK.

They would "continue as long as there is a threat against Turkey," he said.

The multiple air raids mark a shift in policy toward IS by Turkey, a key NATO member. Allies had previously accused Ankara of not doing enough to combat IS after the group seized swaths of Syria and Iraq last year.

With Turkey's lack of participation, the United States resorted to backing PKK-affiliated Kurdish fighters known as the People's Protection Units (YPG) as the US ground ally inside northern Syria. Defense Secretary Ash Carter visited Iraqi Kurdish leaders on Friday.

Turkey's turmoil coincides with political uncertainty as President Recep Tayyip Erdogan's ruling AK party seeks a junior partner after losing its majority in a June 7 election.

PKK: 2013 peace deal 'basically ended'

PKK spokesman Zagros Hiwa told the Associated Press news agency that the Turkish air raids on the PKK camps in Iraq had "basically ended" a 2013 peace deal between Ankara and Kurdish militants.

"The truce has no meaning anymore after these intense airstrikes by the occupant Turkish army," a message posted on the PKK's website read.

Earlier, Davutoglu's office reported that, in a second series of raids, Turkish warplanes had targeted PKK bunkers and other "logistical points" in Iraq's Qandil mountains.

Until the ceasefire largely took hold in 2013, for decades the PKK had sought autonomy via insurgency in southeastern Turkey that claimed tens of thousands of lives.

F-16s 'return safely'

On Saturday, Turkey's official Anatolia news agency reported that all F-16 jets had returned safely to their base in the southeastern city of Diyarbakir.

Turkish border artillery had also shelled PKK and IS sites, Davutoglu's office reported, using an Arabic name for the militia: "Strikes were carried out on targets of the Daesh terror group in Syria and the PKK terror group in northern Iraq."

The Britain-based Syrian Observatory for Human Rights reported that nine IS fighters had been killed in Turkey's initial air raids early on Friday.

More arrests across Turkey

Inside Turkey on Saturday, security forces made more arrests of suspected IS and PKK supporters in Istanbul and other cities. Some 300 suspects had been detained on Friday. On Saturday, Davutoglu said the combined total had risen to 590.

On Friday night, police used tear gas and rubber bullets to disperse demonstrators in Istanbul, where one group of protesters carried the coffin of Gunay Ozarslan, a female activist killed during a raid on leftists earlier in the day.

Fallout from Suruc

Tensions have soared since last Monday's suicide bombing in the Turkish town of Suruc on the border with Syria.

The alleged perpetrator, a 20-year-old Turkish man with links to IS, killed 32 people, mostly young Kurdish activists.

The PKK subsequently claimed responsibility for Wednesday's killing of two Turkish police officers whom the group accused of collaborating on Monday's bombing.

Ankara has long denied accusations that it sided with militants by allowing foreign IS recruits access to Syria via Turkey as part of an agenda to topple President Bashar al-Assad.

Turkey's government had also faced claims that it dodged playing its full role as a NATO member in the yearlong US-led campaign that includes the warplanes and bases of Arab nations and Kurdish ground forces against IS.

Erdogan, Davutoglu change tack

President Erdogan indicated on Friday that Ankara had given the US the green light to use Incirlik, a NATO-used air base, for strikes against IS.

Turkish news agency Dogan said three warplanes had taken off from Incirlik to strike targets inside Syria, but their nationality was not clear.

Davutoglu declined to give details of the US-Turkish agreement on Incirlik's use, saying only that a "decision had been taken for Turkey's own security."

Erdogan said the situation had "got out of control" in recent days and Turkey now had to act differently.

ipj/mg (AFP, dpa, AP, Reuters)