(dpa) - Turkish troops have crossed into Iraq in an attempt to destroy Kurdish rebel bases in the mountainous region with Turkish television reporting Friday that 10,000 troops were involved in the operation.
Turkish soldiers backed by Cobra attack helicopters crossed the border at 19:00 pm (1700 GMT) Thursday evening following a day of air and artillery attacks on suspected Kurdish Workers' Party (PKK) targets in Iraq, the General Staff said in a statement posted on its official website on Friday.
The statement said the military attached utmost importance to the territorial integrity of Iraq, that the operation would be limited and that the troops would return to Turkey in the "shortest time possible."
The NTV private television station reported that 10,000 had crossed the border and by midday Friday had reached 10 kilometres inside Iraq.
"This operation's target is the PKK terrorist organization. It is a continuity of the air operations that have been carried out. Civilians and local elements who do not show hostility to Turkish forces will not be negatively affected by this operation," the statement said.
The military statement said that the aim of the operation was to stop the PKK from using mountainous northern Iraq as a base from which to launch attacks on Turkey. The General Staff has previously estimated that there are around 4,000 to 5,000 PKK guerrillas based in northern Iraq.
Turkish media reported that there had been sounds of fighting on Friday but it was not clear where exactly, or with whom, the Turkish military forces had been fighting.
Prime Minister Recep Tayyip Erdogan also said the operation had no ulterior motives.
"The target, aim, content and the boundaries of the operation are clear. The only target is the PKK camps in northern Iraq. Everyone should know that we have no aim but to secure our citizens' safety and to secure the border. Our armed forces will return in the shortest time possible once they reach their targets," Erdogan said. He added that he had telephoned US President George W Bush on Thursday night to inform him of developments.
The European Union's chief diplomat Javier Solana expressed concern over Turkey's incursion into northern Iraq to fight the Kurdish militants.
Speaking at the conclusion of a meeting of EU defence ministers in Brdo, Slovenia, Solana said that "the (Turkish) action is not the best answer."
He said the EU had fundamental sympathy for Turkey's problems with the PKK, considered a terrorist group by the EU and the United States.
"But the territorial integrity of Iraq is very important to us," Solana said.
The German Foreign Ministry said it was worried about a possible escalation.
The presence of Turkish troops in northern Iraq meant a "not inconsiderable risk of destabilization," Foreign Ministry spokesman Martin Jaeger said.
"A land operation is a whole new level," US Deputy Assistant Secretary of State Matthew Bryza told journalists in Brussels on Friday in reaction to reports of the ground assault.
On Thursday, Iraq's Patriotic Union of Kurdistan reported artillery strikes on several areas in northern Iraq, including Safa Qandil, Qalit Duza, Zarwa, Sinsakir and Raniya.
On Friday, Turkish President Abdullah Gul announced in a statement that he telephoned his Iraqi counterpart Celal Talabani Thursday night informing him of the air strikes and inviting him to Turkey but he did not discuss the land forces operation.
Speculation had been high in Ankara that a cross-border operation would be launched in the near future with Foreign Minister Ali Babacan earlier in the week telling reporters that an operation remained "on the table."
The launch of the operation came as a surprise however as none of the four other large-scale cross-border operations were launched in the middle of winter.
More than 32,000 people have been killed since 1984 when the PKK launched its fight for independence or autonomy for the mainly Kurdish-populated southeast of Turkey.