Imran Khan, a former cricket star, was barred from taking a flight from Lahore to Karachi, said Omar Cheema, a spokesman for Khan's Tehreek-e-Insaf, or Movement for Justice party.

Khan has accused the Mutahida Qaumi Movement, or MQM, a Karachi-based party allied with Musharraf, of stoking violence in the city during a visit by suspended Chief Justice Iftikhar Mohammed Chaudhry on May 12. Some 41 people were killed and dozens were injured, many from gunfire.

Musharraf suspended Chaudhry in March over alleged abuse of authority. The move sparked widespread protests by lawyers and opposition groups, accusing the president of attempting to remove an independent-minded judge to forestall likely challenges to his continued military rule in an election year.