An unmanned US aircraft failed during an attempt to fly at six times the speed of sound in the latest setback for hypersonic flight.

Massive firework displays in US cities rounded off America’s July 4 celebrations – the nation’s 227th birthday.

Hackers operating outside the US tried unsuccessfully to enter the computer network at a top secret US Air Force base, officials said.

Former US President Bill Clinton accepted the Dayton Peace Prize for his efforts to end the war in Bosnia and said the United States must finish the job through financial support.