The Britain-based Syrian Observatory for Human Rights says the air raids overnight took place in four provinces: Aleppo, Raqqa, Hassakeh and Deir el-Zour. The entrance to Syria’s largest gas plant, Conoco in Deir el-Zour, was among the targets. The Observatory says there were casualties in the airstrikes, but that it has no concrete figures. A resident on the Turkish side of the Syria-Turkey frontier says strikes Monday morning also struck the Islamic State-controlled town of Tel Abyad. The town is home to a border crossing. The resident, Mehmet Ozer, says the strikes hit an abandoned military base and an empty school. Air raids believed to have been carried out by U.S.-led forces hit three makeshift oil refineries in northern Syria on Sunday as part of a campaign against Islamic State, a human rights group said. Also Read – Pro-Govt supporters rally as Hong Kong’s divisions deepenThe United States has been carrying out strikes in Iraq since Aug. 8 and in Syria, with the help of Arab allies, since Tuesday, with the aim of ‘degrading and destroying’ the militants who have captured large areas of both countries.Barack Obama has been seeking to build a wide coalition to weaken Islamic State, which has killed thousands and beheaded at least three Westerners. In a potential boost for the United States, a jihadist Twitter account said the leader of an al Qaeda-linked group had been killed in a U.S. air strike in Syria, the SITE service said.A U.S. official said on Sept. Also Read – Pak Army ‘fully prepared’ to face any challenge: Army spokesman24 that the United States believed Mohsin al-Fadhli, leader of the Khorasan group, had been killed in a strike a day earlier, but the Pentagon said later it was still investigating.But in a tweet on Sept. 27, a jihadist offered condolences for the death of Fadhli, SITE, a U.S.-based organisation that monitors militant groups online, said on Sunday.In Washington, Tony Blinken, deputy White House national security adviser, said on Sunday that officials could not yet confirm the death.United States officials have described Khorasan as a network of al Qaeda fighters with battlefield experience mostly in Pakistan and Afghanistan that is now working with al Qaeda’s Syrian affiliate, the Nusra Front.