The Islamic State terrorist group released a video Sunday it says shows the execution of five British men accused of spying. The 10-minute-long video shows five men saying they filmed IS militants in Raqqa in northern Syria. Raqqa is the capital of the Islamic State group’s self-declared caliphate. The men kneeled on the ground. Five men wearing military clothing and masks stood behind them with guns. One of the gunmen said the execution was “a message to David Cameron” -- the British prime minister. Cameron has ordered an increase in attacks on militants in Iraq and Syria. The five alleged spies were then shot in the head. The British foreign office said it was examining the video.