A Turkish observation post in the Idlib region of northern Syria was attacked by mortar fire launched from territory controlled by the pro-Assad forces, Turkey's defence ministry said on Saturday, adding that there were no casualties.
The ministry said a Russian representative in the region had "immediately intervened" to stop the attacks but warned that it had completed preparations to "give the necessary response" if the attacks continued.
There have been similar attacks on Turkish observation posts in the region recently. One Turkish soldier was killed and three others were wounded in an attack on Thursday which the ministry judged to have been deliberate.
Russia, which supports Bashar al-Assad in his country's civil war, and Turkey, long a backer of those rebelling against Assad, co-sponsored a de-escalation agreement for the area that has been in place since last year.
The accord has faltered in recent months, forcing hundreds of thousands of civilians to flee. Idlib is the last remaining bastion for anti-government rebels after eight years of civil war.
Earlier on Saturday, President Recep Tayyip Erdoğan said he had discussed the attacks on Turkey's observation posts in talks with Russian President Vladimir Putin on the sidelines of the G20 summit in Japan.
"We hope these attacks won't happen anymore. There is a calm right now. We never want these, it shouldn't happen again. We discussed these," Erdoğan told a news conference at the summit.
"The presence of these observation posts is to protect Idlib and the region. We will defend our sensitivity on this until the end," he said.
