Speaking a day before parliament was to vote on extending the government's mandate to order cross-border operations, Erdogan said his government was determined to crush the outlawed Kurdistan Workers' Party (PKK), using all available means, including an incursion into Iraq.

Such an operation will be carried out "if need be, at the right time and under the right conditions with a view of obtaining the right result," Erdogan told lawmakers from his ruling party.

"Turkey is in a position of self-defence when it comes to terrorism," he added.

Amid nationwide outrage over the latest PKK violence, parliament is expected Wednesday to overwhelmingly back the motion extending by one-year the government's authorisation for cross-border strikes against PKK rebels who attack Turkish territory from Iraq's autonomous north.

"We will give the strongest response to the attack," President Abdullah Gul said here before departing on a two-day visit Finland and Estonia.

Turkey has long accused Iraqi Kurds of tolerating the PKK presence on their territory and Erdogan issued a fresh warning for them to side with Turkey.

"The best choice for the regional administration of northern Iraq is to cooperate with us against terrorist elements because the terrorist organisation is a cause of regional unrest and tension," Erdogan said.

"It is inevitable for those who cannot put a barrier between themselves and terrorism to be adversely affected by the struggle against terrorism," he added.

Iraqi authorities have repeatedly pledged to curb the PKK, but say the group takes refuge in mountainous regions to which access is difficult.

Earlier Tuesday, the Turkish army announced that warplanes bombed 21 PKK targets in the Avashin-Basyan region in northern Iraq and the Buzul and Iki Yaka mountains near the border in Turkey's southeast.

The raid was the fourth strike against PKK hideouts inside Iraq since Friday's attack on a military outpost, located in a deep valley surrounded by rugged mountains in the border province of Hakkari.

The army has said most of its casualties were caused by heavy weapon fire from northern Iraq as the rebels attempted to take out soldiers stationed on the mountains to ensure the outpost's security.

Twenty-three militants were killed in the ensuing clash that lasted late into Friday night, and the army said Tuesday two more rebels were killed Monday in continuing security operations in the area.

The PKK, on the other hand, claimed that it had killed 62 soldiers and wounded more than 30 while losing only nine rebels.

The casualty numbers are difficult to confirm independently.

Using intelligence passed on by the United States, a NATO ally, the army has staged several air strikes and a week-long ground incursion against PKK targets in northern Iraq last February under a one-year parliamentary authorisation that expires on October 17.

Although the army has described the strikes as successful, it has also called for economic and social measures in Turkey's impoverished Kurdish-majority southeast to erode popular support for the group.

Turkey's civilian and military leaders are expected to meet Thursday to discuss fresh measures to curb the militants.

The talks are expected to focus on five legal amendments requested by the army and the police to beef up the struggle against the PKK, among them extensive stop-and-search powers and the extention of detention periods.

The PKK -- listed as a terrorist organisation by Turkey, the United States and the European Union -- took up arms for self-rule in southeast Turkey in 1984, sparking a conflict that has claimed about 44,000 lives.