Turkish forces struck dozens of Syrian government targets in northwestern Syria on Monday after five Turkish soldiers were killed in an attack on a military base in Idlib province, the Turkish defence ministry said.
The base at the town of Taftanaz was attacked a week after eight Turkish military personnel were killed by Syrian shelling in Idlib following Turkey's deployment of thousands of troops to stem a Syrian government offensive in the rebel-held region.
Hitting back after Monday's attack, in which five Turkish soldiers were also wounded, Turkish forces fired on 115 Syrian government targets and destroyed 101 of them, including three tanks, two mortar positions and one helicopter, the defence ministry said in a later statement.
The incidents are among the most serious confrontations between Turkish and Syrian troops in nearly nine years of conflict in Syria, and Turkey has said it will drive back Syrian forces if they do not pull back by the end of this month.
"Their attacks against our posts have made an operation necessary," Omer Celik, spokesman for President Tayyip Erdogan's AK Party, told reporters in Ankara.
The rapid advance by Syrian government forces in Idlib, the last major enclave of insurgents opposed to President Bashar al-Assad, has driven nearly 700,000 people from their homes towards the closed-off Turkish border.
Turkey, which already hosts 3.6 million Syrian refugees, says it cannot absorb any more and is ready for military action to halt the Syrian government advances.
It has poured 5,000 troops and convoys of military vehicles across the border, carrying tanks, armoured personnel carriers and radar equipment to bolster its existing military positions.
A Turkey-backed Syrian rebel commander said the insurgents had also launched a military operation near the town of Saraqeb, south of Taftanaz, with Turkish artillery support.