Turkish soldiers, air force bombers and helicopter gunships reportedly launched an incursion into Iraq on Wednesday, hours after Kurdish rebels killed 26 soldiers and wounded 22 others in multiple attacks along the border.

Turkish military helicopters fly over the Hakkari province during President Abdullah Gul's visit to southeastern Turkey on the Turkish-Iraqi border, Oct 15, 2011. [Agencies]

Turkish authorities did not immediately confirm the incursion but the chief of the military as well as interior and defense ministers rushed to the border area while Prime Minister Recep Tayyip Erdogan canceled a visit to Kazakhstan.

NTV television, without citing sources, said Turkish troops penetrated as deep as 2.5 miles (4 kilometers) and helicopters were ferrying commandos across the border in what appeared to be a cross-border offensive limited in scope for now. Turkey last staged a major ground offensive against Iraq in early 2008.

Kurdish rebel group the Kurdistan Workers' Party, or PKK, said clashes were taking place in two separate areas close to the mountainous Iraqi-Turkish border.

"We have been clashing with the Turkish forces in two areas since around 3 am today," Dostdar Hamo, a spokesman for the rebel group, said by telephone.

The incursion came hours after the rebels, who are fighting for autonomy in Turkey's southeast, staged simultaneous attacks on military outposts and police stations near the border towns of Cukurca and Yuksekova early Wednesday.

The attacks left 26 soldiers dead and 22 others wounded, the Interior Ministry announced. It was the deadliest Kurdish rebel attack since 1992, according to a tally by NTV television.

Turkish warplanes and artillery units, positioned just inside Turkey, struck Kurdish rebel bases across the border in response, NTV said. Turkey last week pressured Iraq to move to eradicate the rebel bases in northern Iraq, saying its "patience is running out" in the face of rebel attacks directed at Turkey from Iraqi soil.

"No one should forget that those who make us suffer this pain will be made to suffer even stronger," President Abdullah Gul told reporters Wednesday. "They will see that the vengeance for these attacks will be immense."

Around 100 Kurdish rebels were believed to have participated in the attacks, according to the state-run TRT television. The rebels fled to northern Iraq after the attacks as the military shelled their escape routes, NTV said.

The rebels have lately intensified their attacks in the country's Kurdish-dominated southeast, killing dozens of members of the country's security force and at least 18 civilians since mid-July.

On Tuesday, a roadside bomb blast killed five policemen and three civilians, including a 4-year-old girl.

The conflict has killed tens of thousands of people since 1984 as Kurdish politicians pushed for greater cultural and political rights for Kurds, who make up around 20 percent of Turkey's 74 million people, such as the right to education in the mother tongue — a demand that the Turkish government fears could deepen the ethnic divide in the country.

The government has taken steps toward wider Kurdish-language education by allowing Kurdish-language institutes and private Kurdish courses as well as Kurdish television broadcasts. But it won't permit lower-level education in Kurdish.

The European Union, which Turkey is striving to join, has pushed the Turkish government to grant more rights to the Kurds. But EU countries also have urged Kurdish lawmakers to distance themselves from the rebel group, which is considered a terrorist group by the US and the EU.