Pakistan's security forces launched a sweeping midnight raid on supporters of jailed former Prime Minister Imran Khan who had stormed the capital demanding his release on Tuesday, local media said, with hundreds arrested amid chaotic scenes.

Thousands of protesters had earlier gathered in the center of Islamabad after a convoy, led by Khan's wife, broke through several lines of security all the way to the edge of the city's highly fortified red zone.

The red zone, guarded by army soldiers, houses the country's most important offices and buildings, including Parliament and an enclave of foreign missions.