Turkey has launched more air raids against the Islamic State of Iraq and the Levant (ISIL) in Syria and against Kurdish fighters in Iraq.
Saturday's raids are the latest in a campaign that began early on Friday in response to a suicide bombing at a rally in the southern Turkish city of Suruc earlier in the week that killed dozens of Kurdish activists.
Turkey's targets included seven bases in northern Iraq belonging to the PKK, whose Syrian allies are fighting against ISIL.
Turkish officials appeared to be prepared for a long-term fight.
"Whenever we see a decrease in or the vanishing of the threat, then of course we will make a reassessment," Ahmet Davutoglu, the Turkish prime minister, said at a news conference.
"A third wave of operations are a part of this."
The PKK said the strikes on its bases meant the Turkish government had ended a fragile 2013 ceasefire between the two sides.
The president of Iraq's Kurdish Regional Government (KRG) Masoud Barzani, spoke to Davutoglu over the telephone on Saturday and "expressed his displeasure with the dangerous level the situation has reached", according to a KRG statement.
Zeina Khodr reports from Gaziantep:
For Turkey, ISIL declared war when it bombed a cultural centre in the border town of Suruc on Monday. But many believe Turkey's decision to actively engage in the US-led fight against the armed group has as much to do with the battlefield in northern Syria.
The government here is concerned about ISIL threatening Syrian opposition groups in their strongholds in Aleppo.
But Ankara is also worried about what it perceives as the growing strength of Syria's Kurds. The Kurdish YPG militia, which is linked to the PKK, now controls half of the 800km border with Turkey. Turkey said it would be a red line if Kurds created a state in northern Syria.
Officials even blamed US air strikes for helping the Kurds gain ground from ISIL.
"He requested that the issue not be escalated to that level because peace is the only way to solve problems and years of negotiations are better than one hour of war," the statement said.
"Mr Barzani is ready to do anything within his means to assuage this tension and go back to a situation of peace."
In a related development, Turkish police have been rounding up hundreds of suspected ISIL and Kurdish fighters in cities and towns across the country. As of Saturday, nearly 600 people had been detained.
Turkish police fired water cannon and tear gas to disperse about 1,000 demonstrators who had gathered in the capital Ankara to protest against the military strikes.
Peace talks between the PKK and Turkey had started in 2012 but have stalled of late.
"The truce has no meaning any more after these intense air strikes by the occupant Turkish army," the PKK said on its website.
Bahtiyar Dogan, a PKK spokesperson in Iraq, told AFP news agency that one fighter was killed and three wounded in the air strikes, which he said started late on Friday and lasted through much of Saturday.
"We are still committed to the directives of our leader [Abdullah] Ocalan ... but it seems Erdogan wants to drag us back into war," Dogan said.
"When things reach this level and when all of our areas are bombed, I think by then the ceasefire has no meaning any more," he said, echoing the statement on the PKK website.
Turkey's war on ISIL a major policy shift
Turkey earlier this week approved the full use of its airbases by the US-led coalition against ISIL and has been pushing for areas in northern Syria cleared of ISIL fighters to become safe zones.
Turkish fighter jets on Friday morning began pounding ISIL targets in Syria, before following up with raids on PKK positions in Iraq.
The raids were in response to the suicide bombing in Suruc claimed by ISIL that killed 32 young Kurdish activists who were about to deliver aid to Syria's mainly Kurdish town of Kobane.
The PKK responded by killing two Turkish police officers, claiming they collaborated with ISIL in the bombing.
Source: Al Jazeera and agencies