ISLAMABAD, March 12 (Xinhua) -- Police have arrested dozens of people in southern Pakistan's port city of Karachi ahead of lawyers' long march on Thursday, private DAWN NEWS TV channel reported.

    Crackdown against political activists supporting lawyers' long march is continuing across the country as the government puts in place various security measures.

    More than 400 opposition activists in eastern Punjab province have been detained by the police on Tuesday night and Wednesday, local newspaper DAWN reported on Thursday.

    Most of the top leaders of opposition parties that were expected to join the long march have went into hiding after the crackdown started, said the report.

    The DAWN quoted sources as saying that the government had decided to place Pakistan Muslim League-Nawaz (PML-N) leaders Nawaz Sharif and Shahbaz Sharif who were main supporters of the lawyers' movement under house arrest by Friday.

    Nawaz Sharif on Wednesday vowed to change the country's destiny and urged the masses to defy the government efforts to quash the long march.

    Lawyers and political parties across Pakistan planned to start their long march from across Pakistan on Thursday and stage sit-in in Islamabad for indefinite time until the restoration of the judges who were sacked in November 2007 when then-President Pervez Musharraf imposed a state of emergency.