A sickening cycling crash caused jitters at the Rio Olympics on Sunday, as swimming superstar Michael Phelps prepared to launch his quest for glory.

Chinese diving queen Wu Minxia sealed a record fifth diving title and in their debut Games, tiny Kosovo became the 100th country to win an Olympic gold medal.

Dutch rider Annemiek van Vleuten was leading the women's road race when she crashed head-first on the final descent, lying motionless by the road.

Van Vleuten was conscious as she was taken to hospital but riders spoke of their shock over the fall, on a stretch where three cyclists broke bones in the men's race on Saturday.

"It really shook me when I saw Annemiek crashed in the road," said eventual winner and fellow Dutch rider Anna van der Breggen, who rode past her stricken team-mate.

"Annemiek was leading but I realised I was now first in the team. I was shocked."

Fourteen gold medals were up for grabs on the second full day of competition, which saw Russia's drug-tarnished reputation suffer another body blow with news of a ban from next month's Rio de Janeiro Paralympics.

China bagged two golds including the record fifth diving title for Wu, which took her past compatriot Guo Jingjing and American great Greg Louganis.

Air pistol shooter Zhang Mengxue had earlier won the first gold of the Games for China, who finished second on the 2012 tally behind the United States.

- Enter Phelps -

Kosovo, a country of about two million, also had reason to celebrate when flag-bearer Majlinda Kelmendi won the women's 52kg judo title, beating Italy's Odette Giuffrida in the final.

"I have always wanted to show the world that Kosovo is not just a country that has gone through war," Kelmendi said, the Kosovo flag draped around her shoulders.

America's Katie Ledecky made a statement when she swam the second-fastest 400m freestyle in history, breaking the Olympic record and threatening her own world mark, in the heats.

"That one felt pretty easy, so hopefully means I will be faster tonight," said Ledecky, who clocked 3min 58.71sec, close to her world record of 3:58.37.

"We'll see. That's the easiest it's felt going under four minutes."

Ledecky is hot favourite for the final later on Sunday as she bids to complete the first 400m, 200m and 800m Olympic treble since Debbie Meyer in 1968.

Swimming's biggest star, Michael Phelps, is also tipped to make his first appearance, leading the US men's challenge of Australia in the men's 4x100m freestyle relay.

Phelps can extend his record as the most decorated Olympian in history if he adds to his collection of 22 medals -- 18 of them gold -- in the relay.

The day got off to a turbulent start with high winds buffeting venues, causing damage and forcing cancellations and delays to sporting.

The entire rowing schedule at the Lagoa Rodrigo de Freitas venue was scrapped after winds lashed the area, churning the waters and making it impossible to compete.

It came after competitors had hit out at similar conditions on the course on Sunday which led to the capsizing of a Serbian double sculls team.

- Paralympics ban -

There was similar chaos at the tennis venue, where play on outside courts was delayed by 90 minutes as gusts of 25km/h (15mph) barreled through the Barra centre, blowing down umbrellas and toppling hoardings.

Brazilian number one Thomaz Bellucci lashed out at the decision to let his game against close friend Dustin Brown go ahead. Brown retired with an injury after trailing 4-5 in the second set having won the first.

"It was almost impossible. I don't know how they allowed us to play like this. I have never played in these conditions," said 28-year-old Bellucci.

In the women's 10m air pistol, which is held indoors, Zhang produced a perfect 10.9 on her 17th shot to hold off the challenge from Russian teenager Vitalina Batsarashkina.

Security concerns continued as, a day after a bomb scare and the worrying spectacle of a stray bullet hitting a media tent, reports said Portugal's education minister had been mugged in upscale Ipanema.

And there was more controversy for Russian sport as the shockwaves from last month's McLaren report, which detailed an elaborate state-sponsored doping scheme, continued to reverberate.

The IOC backed away from imposing a blanket ban on Russia from the Olympics, allowing a 278-member team to take part in Rio.

However in a scathing announcement on Sunday, the International Paralympic Committee confirmed that Russia would be banned completely from next month's Paralympic Games in Brazil from September 7 to 18.

Source: AFP