ISTANBUL, Turkey - Turkey's military command declared its "unshakable determination" early Friday to defeat Kurdish separatists hours after a roadside bomb killed three Turkish soldiers and wounded six.

Graphic shows locations of Turkey? temporary security zones near the border with Iraq. [AP]

The attack Thursday evening occurred in one of several "temporary security zones" that the military had just declared along the Iraq border during its campaign against the guerrillas.

Authorities blamed the Kurdish rebels for the blast, which came amid increasing activity by Turkish troops along the frontier that has fed concerns the army might stage a large-scale offensive against rebel bases in the predominantly Kurdish region of northern Iraq.

Turkish leaders say guerrillas cross into Turkey to stage attacks in their recently escalated fight to win autonomy for southeastern Turkey, where ethnic Kurds make up much of the population.

In a statement on its Web site, the military's General Staff vowed to fight the rebels and called on all Turks to stand together "to resist in the face of these terrorist actions."

"The Turkish Armed Forces has an unshakable determination in fighting terrorism and it will absolutely give the necessary answer to such attacks," it said.

The bomb targeted a military vehicle near Siirt, a city 46 miles north of the Iraq border, the governor's office said. It killed three soldiers and wounded six other security personnel, including pro-government village guards, the office said.

Turkey has grown increasingly frustrated with the rise in attacks by the PKK rebel movement, and its leaders have sent more troops to the frontier while publicly raising the possibility of sending the army into northern Iraq.

On Wednesday, the military said it was establishing "temporary security zones" near the border. The declaration came the same day that Turkish security officials and an Iraqi Kurdish official said hundreds of Turkish soldiers crossed the border pursuing guerrillas.

Turkey's foreign minister denied there was a cross-border operation. Turkey is an ally of the United States, and US officials have argued against an attack into Iraq, fearing that might drag its Iraqi Kurdish allies into the conflict.

Some think Turkey may hope its military buildup will push the United States and Iraqi Kurds to crack down on the separatists and head off a Turkish offensive.

The military did not say what it meant by "temporary security zones." Some Turkish media said the areas would be closed to civilian plane flights, but others said additional security measures would be implemented in the zones and entry would be restricted.

In a statement posted on its Web site, the military said the zones would be in place until Sept. 9, but gave no other information.

Newspapers said the areas are in Sirnak, Siirt and Hakkari provinces. Sirnak and Hakkari are next to the border, while Siirt is north of the frontier. All three provinces have been the scene of fighting with Kurdish rebels.

Some Turkish officials have said that if troops stage a major incursion into Iraq, they might set up a buffer zone inside Iraq to try to stop rebel infiltration.

Iraqi President Jalal Talabani, a Kurd, cautioned Turkey against such an operation and urged cooperation.

"We ask almighty God to lead all of us to the way of dialogue and negotiation to solve all questions," Talabani told reporters Thursday. "There is a tripartite, American-Iraqi-Turkish committee that is responsible for solving these matters."

Speaking as commander in chief of Iraq's military forces, he said the Iraqi government would not accept foreign interference and "will defend by all means its sovereignty and the independence of the nation."

Turkish Prime Minister Recep Tayyip Erdogan has said an incursion into northern Iraq would require parliamentary approval.

Gen. Yasar Buyukanit, the military chief, said the army was ready for an offensive but the decision was up to political leaders.