Britney Spears rehearses for 'Femme Fatale' tour

Footage of Britney Spears rehearsing for her 'Femme Fatale' tour has appeared online.
The rehearsal clip, which shows the singer preparing for her 26-date jaunt across the US, appeared on YouTube yesterday. 
The one minute preview sees the star performing the track 'How I Roll', which features on her latest album Femme Fatale, in a tracksuit and surrounded by dancers. 
Spears's tour kicks off in Sacramento, California on June 16. 
Meanwhile Spears' latest album Femme Fatale has gone platinum in the US, it has been announced.
The success of the record, her seventh studio LP, brings her total US album sales to over 33 million.
Femme Fatale has also achieved platinum status in Canada and is gold-certified in the UK, France, Mexico, Czech Republic, Brazil, Korea and Singapore. 
She remains the only female artist to have six albums debut at No.1 on the Billboard 200 albums chart.