Turkish warplanes bombed suspected Kurdish rebel positions in northern Iraq and southeast Turkey early Tuesday in new airstrikes responding to an attack that killed 17 soldiers at a military outpost four days ago. The military said its fighter jets attacked 21 rebel positions in Iraq's Avasin Baysan region and Turkish mountains bordering Iraq. The prime minister indicated a new cross-border military incursion could take place. It was the fourth round of airstrikes on Kurdish positions since Friday's attack when rebels of the Kurdistan Workers' Party, or PKK, fired mortar rounds and artillery from Iraq at the military outpost in a Turkish valley. The attack touched off the deadliest battle between Turkish troops and Kurdish rebels in eight months. The military said Tuesday it had recovered two more rebel bodies, raising the PKK death toll in the gunbattles on the ground to 25. The military said it had not determined how many rebels have been killed in the airstrikes. The PKK has been fighting for autonomy in Turkey's southeast since 1984. The fighting has killed tens of thousands of people. Parliament is scheduled to vote Wednesday on whether to extend by another year the military's authority to carry out operations in northern Iraq. The current mandate expires Oct. 17. Prime Minister Recep Tayyip Erdogan suggested Tuesday that Turkey could stage a new incursion into the region in pursuit of the rebels. “If there is a need, necessary measures will be taken at the right time and place in the most effective way, as in the past year,” Erdogan said in a speech to his party's lawmakers in parliament. “Iraq is our neighbor and the people there are our brothers, our relatives. If there is the need, an operation will not target the civilians or Iraq's integrity.” Turkish warplanes have been striking at Kurdish rebels in northern Iraq for the past year, but stepped up attacks after the assault on the outpost. In February, Turkish ground troops crossed into Iraqi territory for a weeklong operation against the rebels. The government is also considering a military request for an increase in powers in combatting rebels. The military has said changes to Turkish anti-terrorism laws, pushed by the European Union, have crippled its ability to fight the rebels and should be revoked while still safeguarding human rights. Friday's attack has caused outrage in Turkey and a nationalist opposition leader called on the government to immediately send ground troops across the border to chase the rebels who strike at Turkey from Iraqi territory. Devlet Bahceli, the leader of the Nationalist Action Party, also demanded that Turkey's leaders set up a security zone inside Iraq that would allow the military to better patrol the border and prevent rebel infiltration. The Turkish-Iraqi border lies on a rugged, mountainous strip that is difficult to control. “The government must immediately show the political determination for a cross-border operation,” Bahceli said. “Turkey must set up a security zone to prevent infiltration from the north of Iraq.” The army, which has complained liberal reforms imposed by the European Union on Turkey under Ankara's accession bid have curbed its ability to combat internal threats, wants the government to expand emergency measures. Turkish media have reported those measures include extending the period under which suspects can be held without charge, the power to conduct searches without a judge's order and banning lawyers during the interrogation of detainees.