Turkish President Recep Tayyip Erdogan’s offer to the West to return to the “regime-change” game in Syria seems to be getting a hardball response from Russia on the ground, fueling uncertainty over the future of Turkish-Russian collaboration in the conflict.

Russian-Syrian air raids in Idlib, where Turkey’s military buildup has come to shield the rebels holding sway in the province, have recently expanded to northern areas under Turkish control since Operation Euphrates Shield in 2016.

Russia fired ballistic missiles on oil facilities in Jarablus and al-Bab March 5, destroying vital economic resources used by Turkish-backed opposition forces. More extensive strikes followed March 21, targeting a gas facility, an oil station and a management building of Watad, the oil company of Hayat Tahrir al-Sham (HTS), near the Bab al-Hawa crossing with Turkey in Idlib. Russian warplanes carried out the attacks, according to the Syrian daily Al-Watan.

In another strike the same day, a missile landed near the headquarters of Faylaq al-Sham, one of Turkey’s principal allies, in the village of al-Qah in southern Idlib, about 3 kilometers (2 miles) from the Turkish border, Turkish media reported. An ammunition depot and a rebel headquarters in northern Idlib were among the other targets. Missile strikes continued the following day, hitting targets in the southern periphery of Idlib. Separately, an attack on a hospital in Atarib in the western Aleppo countryside killed six people, among them a child. Meanwhile, rebels affiliated with Al-Fatah al-Mubin operation room, led by HTS, the main Islamist faction in Idlib, targeted Syrian army forces with rockets and mortar fire in southern and eastern Idlib, including along the M-5 highway.