| DIYARBAKIR, Turkey
DIYARBAKIR, Turkey Turkish warplanes and artillery pounded Kurdish rebels in northern Iraq for a second night, hours after the rebels mounted attacks on security forces in southeastern Turkey.
The Turkish action, the first against rebels holed up in the mountains of Northern Iraq in over a year, marks a stark escalation of the 27-year-old conflict after the collapse of efforts toward a negotiated settlement.
The Turkish military said on Friday warplanes had attacked 28 Kurdistan Workers Party (PKK) targets on Thursday in the areas of Qandil mountain, Hakurk, Avasin-Basyan and Zap.
"In coordination with the air operation, intense artillery fire was directed at 96 targets identified in the same areas," according to a General Staff statement. "Activities in the fight against terrorism will continue decisively at home and abroad."
At least 12 warplanes had taken off late on Thursday from an air base in Diyarbakir, in southeastern Turkey, according to a Reuters witness.
The military had bombarded rebels a day earlier in response to a spate of rebel action in recent months and an ambush on Wednesday that killed nine servicemen.
On Thursday night, the PKK, designated a terrorist group by Turkey, the United States and the European Union, carried out two simultaneous attacks in Turkey's southeastern Siirt province, security sources said.
Militants fired rocket launchers and rifles in an onslaught on a paramilitary gendarmerie post in Eruh, killing two officers and wounding four soldiers. Two PKK fighters were killed in subsequent clashes.
In the nearby district of Pervari, rebels wounded four civilians during similar attacks on security installations.
The guerrillas also clashed with security forces in eastern Tunceli province overnight and one PKK militant was killed, security sources said. Helicopters brought military reinforcements to the area.
SPIRAL OF VIOLENCE
Prime Minister Tayyip Erdogan heralded an apparent change in strategy on Wednesday, saying the government's patience had run out and those who do not distance themselves from terrorism would "pay the price."
It was not clear whether the air assaults might be a prelude to an incursion by land forces, which Turkey has sent into northern Iraq in the past to tackle PKK fighters.
World diplomatic attention has been focused on unrest in Turkey's neighbor Syria and in Libya, where rebels are closing on leader Muammar Gaddafi's forces in Tripoli. But any large-scale Turkish incursion in northern Iraq could inflame ethnic tensions in the area.
The Kurdish conflict also raises domestic passions in Turkey. Further legal action could be taken against Kurdish politicians, currently boycotting parliament and accused of close links to the PKK.
More than 40,000 people have been killed in the conflict since the PKK took up arms for Kurdish self-rule in 1984.
Turkey's National Security Council, chaired by President Abdullah Gul, issued a written statement after a regular meeting on Thursday, saying it would adopt a "more effective and decisive fight in the fight against terrorism."
It did not elaborate on what those measures would be.
The initial air operation drew condemnation from the speaker of parliament in northern Iraq's semi-autonomous Kurdish region.
"This is a clear violation of Iraq's sovereignty," speaker Kamal Kirkuki said. "We strongly condemn the shelling by Turkey and any other party on Iraqi soil."
Last month, the PKK's Ocalan sent word through his lawyers that he had agreed with Turkish officials to set up a "peace council" aimed at ending the conflict. But the mood turned sour after the PKK subsequently killed 13 troops in the biggest attack since the PKK ended a ceasefire in February.
State talks with Ocalan ended in late July and since then his lawyers have been unable to visit him in his island prison near Istanbul. This week a court banned four lawyers from representing him for a year.
(Additional reporting by Jonathon Burch in Ankara and Shamal Aqrawi in Arbil, Iraq, Writing by Daren Butler)