Tens of thousands of people have fled to Syria's border with Turkey in the last few days as the Syrian army advanced further into the opposition's last major stronghold, residents, rights groups and opposition sources said on Wednesday. They left Maarat Al-Numan, a city in Idlib province that has been a sanctuary for families fleeing former rebel areas, as a Russian-led push has come close to capturing the strategic town of Khan Sheikhoun further south. "The flow of cars and vehicles leaving is not stopping," said Abdullah Younis from the city. Rescuers there said around 60,000 people had fled in the last four days alone. On Tuesday, Russian and Syrian jets intensified their bombing of scattered villages and towns around Maarat Al-Numan, with the Al-Rahma hospital in the area struck, residents said. "There were 15 raids on Jarjanaz in less than five minutes," Abdul Rahman Al Halabi told Reuters from the area. Rebels concede most of their fighters have fled Khan Sheikhoun but are providing fierce resistance to the Syrian army, which has secured a foothold in the rebel-held town that was bombed with sarin gas in 2017. State media, broadcasting from the outskirts of Khan Sheikhoun on Tuesday, said government forces were battling militants but had extended their advance and seized a highway running through the town. Capturing Khan Sheikhoun would be an important gain for Moscow and its ally into the northwestern region, where Moscow has helped President Bashar al Assad turn the tide against insurgents in the eight year conflict since stepping up its intervention in 2015. Russia has thrown its weight behind the campaign, which began in earnest at the end of April, conducting thousands of raids and strikes on rebel-held northern Hama and southern Idlib in what Western military experts and opposition figures say is a "scorched earth strategy". Foreign Minister Sergei Lavrov acknowledged on Tuesday that Russia had military personnel on the ground in Idlib province, the Interfax news agency quoted him as saying. The Russian military has previously downplayed its direct role in the advance, where it used mercenaries and special forces as well as directing battles, according to Western intelligence sources. The fall of Khan Sheikhoun ends rebel control over neighboring northern Hama province, where a leading rebel group, Jaish Al-Izza, had been until now defending the three major towns of Latamneh, Kfr Zita and Morek. The latest Russian-backed advance since a ceasefire broke down over two weeks ago has been aided by thousands of new reinforcements including Iranian-backed militias who had been absent from earlier battles. The Syrian Network for Human Rights,(SNHR), which monitors casualties and briefs various UN agencies, said 196 children were among the 843 civilians killed in the Russian and Syrian raids since the campaign began last April. "The bombing has escalated this week and this makes it likely they will win since they are absolving themselves from the rules of war by indiscriminate bombing of civilian areas and use of internationally banned weapons," Fadel Abdul Ghany, chairman of SNHR, told Reuters. Moscow and Damascus, who deny indiscriminate bombing of civilians areas or targeting hospitals, say they are fighting jihadist militants drawn from across the world. — Reuters