Security forces in Pakistan were seen pushing a protester off a 25ft-tall tower of shipping containers during a demonstration that saw nearly 1,000 people arrested.

Pakistani security forces pushed a protester off a 25-foot tall stack of shipping containers as they were accused of opening fire on supporters of Imran Khan at a huge demonstration in Islamabad.

Pakistan's security forces have been accused of pushing a man off a stack of cargo containers during Tuesday's protests in the capital Islamabad, where crowds demanded the release of former Prime Minister Imran Khan.

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.

Pakistan police said Wednesday they had arrested nearly 1,000 protesters who marched on the capital demanding the release of jailed ex-prime minister Imran Khan, after crowds were evicted from the city centre in a sweeping security crackdown.

Pakistani authorities arrested nearly 1,000 supporters of jailed former prime minister Imran Khan who stormed the capital this week to demand his release, the city's police chief said on Wednesday.