At the controls: Robbie Williams

Williams is a special representative for children's charity Unicef, which organised the symbolic event.

The campaign, Break the Silence, aims to raise awareness of the reluctance of many countries to acknowledge the widespread problem of Aids.

Earlier in the year Williams visited Mozambique with Unicef.

He said: "I've seen the way Aids is tearing so many young lives apart, but I've also seen people fighting back - spreading the word about prevention, looking after orphans, supporting each other.

Together we can fight Aids - it will take money and will power, and that's where we need everybody's help

Robbie Williams

"Together we can fight Aids. Unicef has plenty of experience and knows what must be done, but it will take money and will power, and that's where we need everybody's help."

Surveys taken to mark World Aids Day on Friday have shown the young in England and Wales are becoming more complacent about the risks of HIV from unprotected sex.

Compared to a similar survey last year, there were 11% fewer 15 to 24-year-olds telling researchers that the threat of the Aids virus had influenced their lifestyle.

Infection spreading

Worldwide, more than 30 million people are thought to have HIV.

The United Nations Children's Fund said China could have 10 million sufferers within 10 years, unless it acts decisively and soon.

The epidemic has so far claimed more than 20 million lives, and the number of people infected with HIV or Aids continues to spiral upwards.

The progress of the disease can be slowed down with anti-viral drugs, but there is still no cure.

A vaccine to prevent infection is still many years away.