On 13 July 1995, Dutchbat troops witnessed definite signs that the Serb soldiers were murdering some of the Bosniak men who had been separated. For example, Corporal Vaasen saw two soldiers take a man behind the "White House", heard a shot and saw the two soldiers reappear alone. Another Dutchbat officer saw Serb soldiers murder an unarmed man with a single gunshot to the head and heard gunshots 20–40 times an hour throughout the afternoon. When the Dutchbat soldiers told Colonel Joseph Kingori, a United Nations Military Observer (UNMO) in the Srebrenica area, that men were being taken behind the "White House" and not coming back, Colonel Kingori went to investigate. He heard gunshots as he approached, but was stopped by Serb soldiers before he could find out what was going on.