Supporters of President Musharraf fought street battles with those of top judge Iftikhar Muhammad Chaudhry, suspended by the president. Mr Chaudhry abandoned plans to address a rally in the city.

Opposition groups blamed the pro-Musharraf MQM party of organising the unrest, but it denied the claim.

Speaking at a mass rally in Islamabad on Saturday night, Mr Musharraf ruled out declaring a state of emergency and appealed to the country to stand united. He blamed "elements who tried to create turmoil by politicising" Chief Justice Chaudhry's suspension. He also criticised Mr Chaudhry, saying the top judge had ignored warnings against travelling to Karachi.

Mr Chaudhry flew from Islamabad to Karachi on Saturday morning, planning to address a rally in the city. But after landing, he was unable to leave the airport, because roads into the city were blocked. After several hours, Mr Chaudhry abandoned his plans and returned to Islamabad.

BBC