Islamist fighters have seized 17 checkpoints from Syrian forces in clashes around the city of Idlib that have cost at least 71 lives, a monitor said Thursday. "The government and its supporting forces have lost 17 checkpoints and regime locations to the Al-Nusra Front and other Islamist groups in and around Idlib" in the country's **rthwest, said the Syrian Observatory for Human Rights. The clashes come as part of an Islamist offensive launched Tuesday and led by Al-Qaeda affiliate, the Al-Nusra Front, on the regime-held city of Idlib. Calling itself "The Army of Conquest," the new Islamist coalition said on Twitter Tuesday that it was preparing for "the invasion of Idlib" in order "to liberate this good city." Citing eyewitnesses, the Observatory said heavy shelling by the Islamist fighters had forced "regime forces to erect new checkpoints and barricades" in the city.