Children were among at least nine civilians killed Tuesday in Russian strikes on Syria's Idlib, a monitor said, as expectations mount of a government offensive in the country's last major rebel stronghold. Rebel-backer Turkey has held several rounds of talks with regime ally Russia aimed at averting an assault on Idlib, but government troops have been massing near the rebel zone. A full-fledged assault would be devastating for the estimated 2.5 million people living in the northwestern province, many of them rebels and civilians bussed out of other areas that came back under regime control. The United Nations on Tuesday urged Russian President Vladimir Putin and his Turkish counterpart Recep Tayyip Erdogan to hold new talks to avert a "bloodbath" in the northwestern province. The appeal came after Rami Abdel Rahman of the Syrian Observatory for Human Rights said Russian warplanes resumed air strikes on Idlib after a 22-day pause. The Britain-based monitor, which relies on sources in Syria for its reports, said at least nine civilians, including five children from the same family, were killed in the raids, while 10 people were wounded. The strikes targeted 24 areas and "came a day after rebel units in Idlib hit regime positions in neighbouring Latakia province, which killed three pro-regime fighters," Abdel Rahman told AFP. Tuesday's bombardment hit several areas held by the jihadist-led Hayat Tahrir al-Sham alliance, among them the large town of Jisr al-Shughur, but also areas held by rival Turkish-backed rebels, including the town of Ariha. In the town of Muhambal, southwest of the provincial capital city Idlib, firefighters battled a huge blaze at a petrol station which was hit by an strike. Warplanes continued to fly over the area throughout the afternoon, an AFP correspondent said. - A 'dramatic situation' - Seized from government forces in 2015, Idlib and adjacent areas form the last major chunk of territory still in rebel hands. The Syrian military has been deploying reinforcements to the zone for more than a month, and Russia has stepped up its rhetoric. "We know that the Syrian armed forces are getting ready to solve this problem," Putin's spokesman Dmitry Peskov said on Tuesday, calling Idlib a "pocket of terrorism". Moscow has been carrying out strikes in Syria since September 2015, using aircraft based at the Hmeimim base in Latakia province. It accuses rebels in Idlib of attacking Hmeimim with weaponised drones and insists jihadists in the province must be eliminated. French Foreign Minister Jean-Yves Le Drian on Tuesday warned against heading towards a "dramatic situation" for civilians in Idlib. "It is important today that the path to negotiations be open and not that towards confrontation," he told AFP. Analysts say there is still a window of opportunity to avoid the humanitarian impact of a full-scale offensive. The presidents of Turkey, Russia and fellow regime ally Iran are to meet in Tehran on Friday for three-way talks that are expected to focus on Idlib. The UN's Syria peace envoy, Staffan de Mistura, on Tuesday appealed to "President Putin and to President Erdogan... to make a telephone call," even before they meet.