Thousands of supporters of Pakistan’s jailed former Prime Minister Imran Khan broke through barricades around the capital Tuesday and marched into Islamabad, clashing with security forces and demanding his release.

Pakistani protesters demanding the release of ex-prime minister Imran Khan on Tuesday killed four members of the nation's security forces, the government said, as the crowds defied police and closed in on the capital's centre.

Supporters seeking the release of imprisoned Pakistani former Prime Minister Imran Khan broke through a ring of shipping containers blocking off the capital on Tuesday, and battled security forces despite a government threat to respond with gunfire.

Thousands of supporters of Pakistan's jailed former Prime Minister Imran Khan marched on the capital Islamabad this week, breaking through barricades and clashing with police in response to his call for a sit-in protest.

At least six people have died in protest-related violence as supporters seeking Imran Khan’s release from prison broke through barriers meant to lock down Islamabad.