Turkey has massed up to 100,000 troops near the mountainous border, backed up by tanks, artillery and warplanes. Saturday's strike did not appear to be the long-awaited major operation by NATO member Turkey to destroy rebel bases.
"This is a limited operation condoned by the international community. I don't expect to see an escalation of violence," said Milliyet newspaper columnist Semih Idiz.
RESTRAINT
Ankara has made many threats of military action but, under heavy U.S. pressure, has so far shown restraint. Washington fears a large-scale operation could wreak havoc in the most stable part of Iraq and possibly the wider region.
Erdogan said before the army statement he hoped to get the "most effective" result from an operation.
"Our armed forces were authorised as of November 28. We will watch and follow the process after this," Erdogan said.
Turkey's parliament approved a resolution on October 17 giving the government the legal basis to order cross-border military operations if and when it deemed them necessary.
The resolution, approved by an overwhelming majority of lawmakers, followed a series of deadly PKK attacks on Turkish security forces that fanned an angry wave of nationalism across Turkey, a NATO member that also wants to join the EU.
It is valid for one year, and the cabinet decision this week effectively frees up the generals to act as they see necessary without seeking further political approval.
Erdogan held emergency talks with U.S. President George W. Bush on November 5 in the White House, wringing from him pledges of closer cooperation, including more intelligence sharing against a group Washington also brands as terrorist.
Northern Iraqi Kurdish authorities have also taken steps to stop supplies reaching the PKK rebels in the mountains.
Ankara blames PKK for the deaths of nearly 40,000 people since the group began its armed separatist insurgency in 1984. Both the European Union and the United States list the PKK as a terrorist organisation.
