The 30-something Spice Girls announced plans for a 11-city world tour this winter, confirming in London one of the worst-kept secrets of the past few weeks.

All five Spices -- Victoria "Posh" Beckham, Melanie "Scary" Brown, Emma "Baby" Bunton, Geri "Ginger" Halliwell and Melanie "Sporty" Chisholm -- attended the news conference Wednesday at London's O2 Arena, E! News reported Thursday.

"We are girl power," said Halliwell. "It doesn't matter how old you are, five or 65."

The tour will kick off Dec. 7 in Los Angeles, with stops in Las Vegas, New York, London, Cologne, Madrid, Beijing, Hong Kong, Sydney and Cape Town before wrapping up Jan. 24 in Buenos Aires.

The popular '90s group was first rumored to be reuniting for the 2005 Live 8 concerts. The rumor mill picked up earlier this year, with speculation that the quintet would regroup for the Princess Diana tribute concert this weekend or the Live Earth concerts on July 7. But again, no: Brown recently gave birth to a girl, Bunton is pregnant and the Beckham family is in the middle of a move to Los Angeles.

The tour will mark the first time they perform as a fivesome since 1998.