Janet Jackson Postpones Concert Dates

Janet Jackson has postponed two of her concerts this week, claiming an undisclosed illness, a rep for the singer said Tuesday.

Jackson, 42, postponed her Wednesday show in Boston and a Thursday show in Philadelphia.  The announcement comes one day after the singer suddenly fell ill during a soundcheck in Montreal.  She was rushed to the hospital, which forced her to cancel Monday night's show.  Jackson has since been released, but the nature of her illness has not been reported.

As of now, her Rock Witchu Tour will resume Saturday in Greensboro, North Carolina.