Archery world record

Although no medals will be awarded until Saturday, the women's soccer tournament started on Wednesday, and on Friday South Korean archers set the first world records of the Games.

Im Dong-hyun, who suffers from severe myopia and just aims at "a blob of yellow colour", broke his own 72-arrow world record with a score of 699 out of a possible 720, leading his two colleagues to a record combined score as well.

The Games' first medals will be decided in the women's 10 metres air rifle final on Saturday, with the big action coming in the men's cycling road race, where world champion Mark Cavendish is favourite to become Britain's first gold medallist.

In the evening, Americans Michael Phelps and Ryan Lochte are scheduled to line up for a classic confrontation in the men's 400 metres individual medley final.

Phelps, competing in seven events after winning a record eight gold medals four years ago in Beijing, is bidding to become the first swimmer to win gold in the same discipline three times in a row.

"This is going to be a special race," said Gregg Troy, head coach of the American men's team. "I can't imagine a better way to promote our sport than a race like this on the first day."