Russian-backed Syrian regime forces pushed deeper in their offensive on the last remaining opposition stronghold in the countrys northwest on Sunday, getting very close to a Turkish observation post in the area. The Britain-based Syrian Observatory for Human Rights and the oppositions Syrian Civil Defense, also known as White Helmets, reported shelling and airstrikes on opposition-held villages in Idlib province on Sunday, saying that at least one civilian was killed. Idlib has been at the center of a Syrian forces push under the cover of intense aerial strikes in recent weeks, with more than a dozen villages captured. The offensive has already forced tens of thousands of civilians to abandon their homes and flee, including thousands who crossed into neighboring Turkey seeking safety. The attacks resumed after a cease-fire in force since the end of August collapsed recently. Saraqeb and Maaret al-Numan are two major opposition-held towns on the highway linking the capital, Damascus, with the northern city of Aleppo, Syrias largest. The two towns have been emptied of civilians since becoming the target of the offensive, which aims to reopen the highway, closed since 2012. Syrian troops, advancing from the east toward Maaret al-Numan, neared the Turkish observation post outside the village of Surman from three sides, according to the Observatory. The Step news agency, an activist collective, said regime troops were now about 4 kilometers from the Turkish post. Syrian state media made no mention of the post but said government forces captured several villages near Maaret al-Numan. Turkey has 12 observation posts in the northwest, part of a deal with Moscow and Tehran in 2017 to avert large-scale fighting in Idlib. Four months ago, Syrian troops captured all territory around another Turkish post in the village of Morek, also in Idlib province, leaving the Turkish monitors only a nearby road to use. No friction has since been reported between Syrian and Turkish troops in Morek.