Pop superstar Rihanna has accused troubled stars Britney Spears and Lindsay Lohan of not doing enough to tackle their personal problems.

The Umbrella hitmaker has urged the pair to get their lives back on track but insists no one can do anything to help unless they decide to sort themselves out.

She tells British magazine Cosmopolitan, "There's nothing I can say that'll change their minds about their lifestyles. They have to make the change for themselves and I don't know if they want it bad enough."

-Rihanna Pictures
-Britney Spears Pictures
-Lindsay Lohan Pictures

(This news article provided by World Entertainment News Network)