Thousands of supporters of Pakistan’s former prime minister, Imran Khan, have been joining a march

For four days, thousands of supporters of Pakistan’s former prime minister, Imran Khan, have been joining a march on the capital Islamabad in a bid to pressure the government to hold early elections.

The march is set to spread across the country and aims to reach the capital this Friday. It is the culmination of months of rallies held by Khan, and the biggest challenge to Pakistan’s entrenched military establishment since he was ousted from power in April this year.

Khan, a staunch critic of U.S. policy in the region who during his premiership forbade Washington from using Pakistani soil for operations in Afghanistan, was removed from power following a no-confidence vote in parliament. Khan has accused the U.S. of being behind his ousting, and he has refused to withdraw from Pakistan’s political scene, winning several by-elections since.