A high-ranking United Nations official has begun her mission to press the Syrian government to allow investigators to visit the site of a suspected chemical attack near Damascus. The government of Syrian President Bashar al Assad, meanwhile, has sought to blame rebels for the attack, which last week killed hundreds of people with poisoned gas. The incident could prove to be a turning point for Western involvement in the war. The United Nations official, Angela Kane, the high representative for disarmament affairs, was sent to Syria by Secretary General Ban Ki-moon to urge the Syrian government to let a team of investigators visit the attack site. Kane has not spoken to reporters since her arrival in Damascus.