Two women snowboarders were carried off the Rosa Khutor Extreme Park course on stretchers following crashes during qualifying at the Sochi Olympics.
The crashes came one day after Russian skicross racer Maria Komissrova suffered a serious spinal injury during a crash on the same slope.
Komissarova, 23, had more than six hours of surgery.
In the February 16 crashes, Helene Olafson of Norway and Jacqueline Hernandez of the United States fell and required medical attention.
The U.S. team said Hernandez suffered a concussion and has withdrawn from the competition.
International Olympic Committee (IOC) spokesman Mark Adams expressed condolences over Komissarova’s injuries, but said the course was approved by sport federations and there were no big causes of concern over safety questions.
"At this stage we don't see anything abnormal compared to Vancouver [Olympics in 2010] in terms of accidents and injuries -- by the way, in no way to minimize the accident yesterday," Adams said.
"It was a serious one and obviously our thoughts go out to [Maria Komissarova] and we wish her a quick recovery -- but in terms of the level of monitoring that we've done, we don't have any kind of different data that we've had from previous Games."
Later on the Extreme Park course, Eva Samkova won the women's snowboarding cross gold medal to secure the first gold medal for the Czech Republic at Sochi.
In another development, India has raised its national flag in Sochi, marking the country’s return to the Olympics following a ban over corruption.
The International Olympic Committee (IOC) last week lifted its suspension of India that was imposed in December 2012. The step came after new Indian Olympic officials were elected to replace officials who had been tainted by corruption.
The flag was raised at the Rosa Khutor Olympic Village. India's three winter Olympians had marched under the Olympic flag at the Sochi opening ceremony on February 7.
Indian Olympic Committee President N. Ramachandran said the removal of the ban was an “emotional” moment for the Olympic movement of the world’s second most-populous country.
In the competition on February 16, Sweden’s team won the gold medal in the men's cross-country skiing 4 x 10-kilometer relay.
The Russian team finished more than 27 seconds behind Sweden to win the silver medal, while France’s team claimed the bronze.
Russian President Vladimir Putin was in the crowd for the race.
On February 15, Sweden’s women’s 4 x 5-kilometer relay team won the gold medal.
Elsewhere, Kjetil Jansrud of Norway won the men's Alpine skiing super-G gold medal.
Andrew Weibrecht of the United States won the silver medal, while American Bode Miller and Jan Hudec of Canada shared the bronze.
It was Miller’s sixth Olympic medal of his career, making him the second-most winning Alpine Olympic skier in history, behind Kjetil Andre Aamodt of Norway, who won eight medals.
Based on reporting by Reuters, AP,and dpa