Comment on Syria rebels battle regime in Aleppo operation

Beirut (AFP) - Two coalitions of Syrian rebels battled to advance in government-held western Aleppo on Saturday, seizing an army barracks in one district but being pushed back in others.The fighting in the country's former economic powerhouse is some of the fiercest since the Syrian conflict arrived in the northern city in mid-2012.The Islamic State group, meanwhile, released a video showing teenage members executing 25 Syrian soldiers in an amphitheatre in the ancient ruins of Palmyra.And government forces launched a major operation to recapture Zabadani, the last opposition-held town in the Qalamun region near Damascus.The Syrian Observatory for Human Rights reported heavy clashes in several parts of western Aleppo.It said fighters from the Conquest of Aleppo alliance of mostly moderate forces had captured a former research centre being used as a military barracks, opening up lines of attack against several nearby regime-held districts.On Saturday, fierce clashes raged around the complex as regime forces backed by air strikes sought to recapture it.Conquest of Aleppo and a second rebel grouping, Ansar al-Sharia which is dominated by Islamists and Al-Qaeda's local affiliate Al-Nusra Front, began operations against government-held districts of Aleppo this week.The attacks have prompted heavy fighting and bombardments, with rebels firing hundreds of rockets and the government launching dozens of air strikes.The assault began on Thursday, when Ansar al-Sharia attacked several neighbourhoods including Zahra, where an air force intelligence facility is based.The coalition initially made progress, but was pushed back by government forces and heavy air strikes that killed 29 rebels on Friday night, the Observatory said. - First progress since 2013 - Thomas Pierret, a professor at the University of Edinburgh and a Syria expert, said the latest fighting could prove significant.The recent rebel progress in and around western Aleppo "is the first real progress by the rebels in Aleppo since...