Syrian forces launched an offensive to take the last rebel-held territory in Idlib late April, leading to the collapse of a ceae-fire negotiated by Turkey and Russia last year. Turkey set up 12 posts in Idlib as part of the de-escalation zone agreement struck with Russia and Iran in September 2017.
The Syrian Observatory for Human Rights said airstrikes from Syrian warplanes struck the southern edge of the rebel-held enclave with nearly 42 raids, including one that hit near the Turkish observation point in Morek that resulted in a fire in the area.
The strike solicited a Turkish response against Syrian government positions, the first such retaliation, which included missiles and rockets as well as auxiliary attacks launched by Turkey-allied Syrian fighters.
The Syrian strike on Morek is the second such targeting of Turkish forces this week, following an attack Thursday when three Turkish soldiers were injured at an observation point in Sheir Maghar. Turkey's Foreign Minister Mevlut Cavusoglu said Sunday that the country would not tolerate Syrian military attacks on its troops. "We'll put you in your place. Everyone should know their place," he was quoted as saying by the official Anadolu news agency.
Russia supports Syrian President Bashar Assad while Turkey backs opposition groups. The Turkish military said Russian officials were contacted after Sunday's attack.