Caribbeans look to dominate short distances

Caribbean runners bid to expand their dominance of the shorter track distances, after Jamaica's Usain Bolt ran the second quickest 100 metres ever to swat aside any doubt that he is still the fastest man on Earth.

Bolt's gold put him on course for a unique double-double in 100m and 200m races at successive Games, and kept Jamaica on track for a second sweep of individual sprint medals after Shelly-Ann Fraser-Pryce retained her women's 100m crown.

Fraser-Pryce lines up in the first round of the 200m on Monday alongside her team mate and defending champion Veronica Campbell-Brown, and American challengers Allyson Felix and 100m silver medallist Carmelita Jeter.

Meanwhile, 19-year-old world champion Kirani James from the Caribbean island of Grenada looks in commanding form for the 400m final, with almost all the fastest qualifiers coming from the region, apart from the Belgian identical twins Jonathan and Kevin Borlee. Reigning champion LaShawn Merritt of the United States is injured.

And Javier Culson is aiming to become the first person from Puerto Rico to win an Olympic medal in the men's 400m hurdles final, having come into the Games with the world's fastest time.

But the race looks tight, with 2004 champion Felix Sanchez, a national hero in the neighbouring Dominican Republic, surprisingly beating Culson's time in qualifying.

America's Angelo Taylor, at 33 a year younger than Sanchez, is bidding to become the first man to win three Olympic 400m hurdles titles after gold in 2000 and 2008.