Hamburg - Beijing Olympic superstars Usain Bolt and Michael Phelps return to action from a rocky lay-off in somewhat unfamiliar surroundings.

The Jamaican three-time sprint Olympic champion Bolt takes to the streets of Manchester, England, for a 150 metres race.

Phelps, who bagged a record eight golds last year in the Chinese swimming pool, is in Charlotte, North Carolina, for a Grand Prix meet.

Bolt and Phelps were hailed as the biggest stars of the Beijing Games but the headlines were not all positive in the aftermath.

Phelps received a three-month ban after a photo depicted him inhaling from a marijuana pipe.

Bolt, for his part, had to retract statements that marijuana was part of the Jamaican culture and last month crashed his BMW car.

The 100m, 200m and 4x100m Olympic champion and world record holder had to have thorns removed from his foot after the accident but could resume training soon afterwards.

Now he comes to Europe for the street race which is to bring athletics closer to the people again.

Street races were popular in 19th century Britain and Bolt will be up against Britons Marlon Devonish and Mark Lewis-Francis, among others, on a tartan track in downtown Manchester.

"I am looking forward to the upcoming races and I am trying to get myself back on form and to compete because a lot of the other guys are training hard to beat me," said Bolt earlier in the week.

The ardent Manchester United fan also will watch his favourite football club on Saturday at Old Trafford against Arsenal, in which Cristiano Ronaldo's team require only a draw to wrap up the Premier League title. Bolt will meet the team as well.

The 22-year-old then returns to the proper stadium track for a June 11 meet in Toronto as he aims to get ready for the August 15-23 worlds in Berlin.

The swimming world championships take place a few weeks earlier in Rome. Phelps, who briefly toyed with retirement after the marijuana affair, will be there but not on the gruelling eight-race schedule from Beijing.

In Charlotte, Phelps will swim in the 100m freestyle and backstroke races, and like Bolt in Manchester hopes to bring his sport to the centre of attention.

"With the positive and the negative things, there's a lot more attention being brought to the sport. That's something this sport needs and something it deserves," he told a news conference on Thursday.