Sprint sensations Usain Bolt and Yohan Blake began their seasons by competing in 400metre races in their native Jamaica.

Four Jamaican athletes who produced positive tests at their National Championships in June have been suspended for three months.

Five Jamaican athletes who were cleared after producing positive tests at their national trials in June are allowed to compete at the World Championships, although an independent panel hearing an appeal against the decision has yet to sit.

Four of the five Jamaican athletes who produced positive samples at their national trials in June are likely to hear their fate on Monday after their disciplinary hearings concluded yesterday.