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.

Authorities have reopened roads linking Pakistan’s capital with the rest of the country, ending a four-day lockdown, after using tear gas and firing into the air to disperse supporters of imprisoned former Prime Minister Imran Khan who demanded his release from prison.

Islamabad Police Inspector General Ali Nasir Rizvi confirmed that 954 individuals had been arrested between Sunday and Tuesday, as protesters came within 1.6 kilometers of their intended target. The government reported at least one police officer and four paramilitary personnel were killed during the clashes.