Air Security International reported yesterday that at least three “explosive devices” detonated at approximately 4:30 a.m. local time on March 24 and bomb disposal technicians disarmed two others in Grand Junction, Colo. According to ASI, the devices were found outside the homes of employees of Serco Group, a company that operates the control tower at Grand Junction Walker Field Airport. No injuries were reported in the explosions. The airport’s control tower was evacuated in response to the incident. Although no claims of responsibility were immediately made, federal investigators have issued an arrest warrant for a former Serco employee who was fired two years ago while working as a controller at Walker Field. ASI said that during the tower evacuation and security sweep of the airport, air traffic handled by Grand Junction was turned over to controllers in Denver for approximately one hour.