The men's BMX competition at London Velopark got under way Wednesday as riders competed against the clock in seeding runs. There were two spectacular crashes, so expect a few more in the next two days.

"The course is dangerous, but it's the case with most of the BMX courses, especially when you're pushing to the limits," Raymon van der Biezen of the Netherlands told The Associated Press after posting the best time. "You can definitely expect more crashes in the quarterfinals."

Latvian rider Edzus Treimanis went over his handlebars and landed face first. He knelt on the ground with blood running from his helmet, then revealed a cut to his forehead before limping off.

Despite the crashes, British rider Liam Phillips was pleased with the course.

"It's fantastic, absolutely fantastic," he said. "It's truly Olympic standard. There will be crashes, hopefully I will not be on the receiving end of one, but ... that's one of the things that attract general members of the public to the sport."

BMX is making its second appearance at the Games, following a successful debut in Beijing four years ago.

To watch the men's BMX semifinals live click here.

Here's a complete list of the riders competing in the two semifinal heats:

Heat 1

Heat 2