Syrian regime forces made significant advances on Sunday in the countrys northwestern Aleppo province, seizing most of the opposition-held region. State news agency SANA reported 30 villages and towns around the city in the western Aleppo countryside were captured on Sunday. Rami Abdul-Rahman, the head of the Britain-based war monitor Syria Observatory for Human Rights, confirmed the report. “This means the control of Aleppo (city), and the countryside and securing all of Aleppo,” Abdul-Rahman said. On Sunday, Russian warplanes mounted heavy air strikes in the Aleppo province, bombing towns including Anadan, which was later seized by Syrian forces supported by Iranian-backed militias, activists reported. The fighting in the Aleppo region and nearby Idlib province has unleashed a humanitarian crisis. Over 800,000 civilians out of nearly 4 million living in the enclave have been displaced, living in open fields and temporary shelters for the most part in harsh winter conditions. The armed opposition is now squeezed into a shrinking area of nearby Idlib province, where the government is also on the offensive. A car bomb exploded on Sunday in the Syrian town of Tel Abyad, near the Turkish border, killing four people, Turkeys state-run Anadolu news agency said. The Arab town, from which Turkish-backed forces last October pushed out the Syrian Kurdish YPG, has seen a spate of car blasts that has killed dozens of civilians. There was no immediate comment from the authorities. Anadolu, citing security sources, said the attack was carried out by the YPG, which Turkey considers a terrorist group linked to Kurdish insurgents on its own soil. As Syrian forces continued their push to retake Idlib, Turkish Foreign Minister Mevlut Cavusoglu said on Sunday he told his Russian counterpart that attacks in Idlib must stop immediately and that a lasting ceasefire has to be achieved. "We told (Russia on Saturday) ...that the aggression in Idlib must stop and that a lasting ceasefire has to be achieved now," Cavusoglu told reporters during a briefing at the Munich Security Conference, adding that Turkish and Russian officials will discuss the issue in Moscow on Monday. Cavusoglu also said he met with some US lawmakers at the conference, and added Washington should work to improve its relations with Ankara anyway, not just due to current tensions between Turkey and Russia. Turkey, which backs opposition fighters, has been outraged since Syrian attacks in the Idlib region killed 13 Turkish troops in two weeks. It has urged Russia to stop the attacks, warning it would use military power to drive back the Syrian forces unless they withdraw by the end of the month.