Massive manhunt under way after Trump ally shot dead in Utah

A sheriff monitors the scene at Utah Valley University after Charlie Kirk was shot (Lindsey Wasson/AP)

A massive manhunt is under way for a sniper who assassinated Charlie Kirk, a conservative activist and close ally of President Donald Trump, in the latest act of political violence in America.

Mr Kirk was killed by a single gunshot fired from a distant rooftop at the Utah Valley University campus, where he was speaking on Wednesday.