At least 12 Turkish soldiers have been killed in a clash with Kurdish rebels near the Iraqi border. Turkish Prime Minister Tayyip Erdogan calls crisis talks which may authorise a cross-border military offensive. Kurdish rebels killed at least 12 Turkish soldiers and wounded 11 others on Sunday (October 21) in an ambush in mountains near the Iraqi border, security sources said. Fighting was continuing between troops and rebels in the border area, they said. The attack, one of the worst in more than a decade by rebels of the outlawed Kurdistan Workers Party (PKK), came four days after the Ankara parliament backed a motion allowing troops to enter northern Iraq to fight guerrillas hiding there. In another incident on Sunday, a landmine killed one civilian and wounded at least 13 more in a minibus travelling near to where the soldiers were killed. Turkish Prime Minister Tayyip Erdogan called crisis talks that may authorise a cross-border military offensive. Speaking at an Istanbul polling station after voting in Sunday's referendum on constitutional changes, Erdogan said military and government officials would meet at 8 pm (1700 GMT) under the chairmanship of President Abdullah Gul at the presidential palace to decide how Turkey should respond. Turkey's military general staff said 12 soldiers and 23 rebels were killed in Sunday's clashes. Security sources had said earlier at least 13 Turkish soldiers had been killed. The United States, Turkey's NATO ally, and the Baghdad government have urged Ankara to refrain from military action, fearing this could destabilise the most peaceful part of Iraq and possibly the wider region. The PKK ambush, which wounded up to 16 people, occurred in Hakkari province in the mountainous border area early on Sunday. The pro-PKK Firat news agency said the rebels had taken "many hostages" among the Turkish troops. The report could not be independently confirmed. Turkey has deployed as many as 100,000 troops along the border to try to stop the PKK rebels crossing from Iraqi bases to stage attacks inside Turkey. Erdogan's government is under pressure from public opinion and the powerful military to take action against the PKK following a series of deadly attacks on Turkish security forces.