Opposition group Hayat Tahrir al-Sham (HTS) and allied Turkish-backed factions reached Syria’s second city of Aleppo Friday, as they pressed a lightning offensive against forces of the Iranian- and Russian-backed government.The fighting is some of the deadliest in years, with 255 people killed, according to the Syrian Observatory for Human Rights.Most of the dead have been combatants but the toll also includes 24 civilians, most killed in Russian airstrikes.For all the latest headlines follow our Google News channel online or via the app.The offensive began on Wednesday, the same day that a fragile ceasefire took effect in neighboring Lebanon between Israel and Iran-backed militant group Hezbollah.By Friday, the HTS and its allies had wrested control of more than 50 towns and villages in the north, according to the Britain-based Observatory, in the government’s biggest loss of territory in years.They then entered western districts of Aleppo, a city of some two million people that was