Thousands of supporters of Pakistan’s imprisoned former premier Imran Khan have defied a lockdown and mass arrests to head to the capital to demand his release.

The rally has been declared illegal and Islamabad is under lockdown [EPA] At least one policeman has been killed and more than 50 injured, Pakistan’s authorities say, as officials try to stop thousands of opposition protesters reaching Islamabad.

Thousands of Imran Khan supporters marched closer to the capital of Islamabad on Monday demanding his release from prison as authorities braced to prevent the crowd from entering the city.