By Ibon Villelabeitia
UPDATE 3: 15 soldiers and 23 Kurdish rebels killed in rebel attack near Iraqi border.
Fifteen Turkish soldiers and 23 Kurdish rebels were killed after an audacious rebel attack near the Iraqi border, the army said Saturday, in the bloodiest skirmish in a year.
The attack by Kurdistan Workers' Party (PKK) rebels on a military post is likely to ratchet pressure on Ankara to hit back at the militants who use rear bases in neighbouring northern Iraq to strike.
Turkish Prime Minister Recep Tayyip Erdogan said he had cancelled a two-day visit to Mongolia and would immediately return home from Turkmenistan to discuss Ankara's reponse.
An army spokesman said that fighting erupted Friday afternoon when a group of rebels attacked a border post in Semdinli town, Hakkari province, under cover of heavy weapons' fire from bases in northern Iraq.
"Most of our losses were caused by heavy weapons' fire from the north of Iraq," General Metin Gurak, the head of the general staff's press department told the Anatolia news agency.
Turkish forces responded with artillery fire and attack helicopters pounded rebel positions while additional forces were dispatched to the area.
Turkish fighther jets and artillery units also struck at a group of rebels in the north of Iraq, about 10 kilometres from the station which was attacked.
"Twenty-three terrorists were neutralised in the clashes. It is not yet clear how many terrorists were killed by artillery fire and in the strikes by the air force," Gurak said.
He added that two soldiers remained unaccounted for after the fighting which lasted late into Friday night and that a search was underway to find them.
Gurak initially said two soldiers were wounded in the fighting, but Prime Minister Erdogan, speaking in televised remarks from Turkmenistan, raised the number to 20.
"Our stuggle [against the PKK] will continue with determination. We will discuss what methods we will follow in this struggle," he added.
Anatolia reported that Erdogan was expected to chair a meeting of civilian and military leaders at 1400 GMT in Ankara to assess the developments.
Friday's attack comes a day after the end of a three-day ceasefire the PKK announced for Eid Al-Fitr, the Muslim festival marking the end of Ramadan, the holy month of fasting.
The PKK - considered a terrorist group by Turkey, the United States and the European Union - has been fighting for a separate state in the mainly Kurdish southeast of Turkey since 1984.
According to figures recently released by the Turkish army, the 24-year campaign by the rebels had cost the lives of 32,000 Kurdish rebels, 6,500 members of the security forces and 5,500 civilians.
Turkey claims that thousands of PKK militants are holed up in rear bases in the Kurdish-run north of Iraq from where they stage cross-border attacks on Turkish targets.
Ankara also accuses the autonomous Kurdish administration in northern Iraq, of failing to take steps against the rebels who it says are able to move freely in the mountainous enclave and obtain arms and explosives.
The Turkish army, under a one-year parliamentary authorisation obtained last October, has carried out air strikes and a week-long ground incursion against PKK targets, using intelligence passed on by NATO ally United States.
The authorisation expires on Oct. 17 and the Turkish government said last week that it will ask parliament to extend the mandate by one year.
Lawmakers returned from summer recess on Oct. 1 and are expected to vote on the matter in the coming weeks.