Record, scares as Rio starts with a bang

Britain's Adam Peaty was the early star in the swimming pool as he set an eye-popping new world record of 57.55 sec in the men's 100 metre breaststroke heats

A scorching world record, a horrific leg break and bomb and bullet scares made for a hectic first day as the Rio Olympics swung into action.

Vietnam and Thailand won their first ever Olympic gold medals and there was joy for teenage American markswoman Ginny Thrasher, who snared the first gold of the Games on Saturday.

Elsewhere Belgium's Greg Van Avermaet won a crash-filled men's cycling road race and rugby returned to the Games after a gap of 92 years.

Britain's Adam Peaty was the early star in the swimming pool as he set an eye-popping new world record of 57.55 sec in the men's 100m breaststroke heats -- his first ever Olympic swim.

"Fifty-seven-five, not too shabby," shrugged Peaty, adding: "I wasn't even pumped up."

China's Sun Yang headlines the swimming finals later on Saturday when he defends his 400m freestyle title against Australia's Mack Horton.

The Rio Games started with an unwanted bang when a military bomb squad detonated a suspicious package near the finish of the men's cycle race at Copacabana beach, causing jitters among onlookers.

"The security services found a suspicious package close to the cycle road race finish line in Copacabana and as a precaution decided to perform a controlled explosion," Rio Games organisers said.

At the equestrian venue at Deodoro, which is on a military base, a stray bullet ripped through the media centre's canvas roof and landed on the floor.

"All authorities assured that the bullet was a stray bullet that has nothing to do with the Games or the Olympic family or the press. The area was not a target," said Games spokesman Mario Andrada.

America's Thrasher, 19, upset China's Du Li and Yi Siling, the 2012 gold-medallist, to win the women's 10m air rifle competition on her final shot.

Later Hoang Xuan Vinh wrote his name in the history books when he won the men's 10m air pistol, claiming the first ever gold medal for communist Vietnam.

"It's the first gold medal in Vietnam's history, I feel very lucky," said the modest, 41-year-old military officer.