Islamabad had been put under lockdown, with a heavy security presence deployed in anticipation of clashes with convoys of PTI supporters.
The convoys were led by PTI leader Ali Amin Gandapur and Khan’s wife Bushra Bibi, who was released from prison in October and has since taken a more prominent role in trying to mobilise support for Khan.
Reports say Gandapur and Bushra Bibi have left Islamabad and returned to Khyber Pakhtunkhwa province, where their convoy had come from.
Protesters were reported to have responded to a “final” call from Khan, asking them to “fight till the end” until their demands are met.
Their destination was D-Chowk near central government buildings in Islamabad, and the site of political rallies and protests since the 1980s.
But only some of the protesters made it that far.
By Tuesday evening – just hours after protesters first reached the square – security officers had successfully cleared the area. As darkness fell, the lights were switched off – with only police officers and paramilitary soldiers left behind.
Khan has been in prison for more than a year on charges he says are politically motivated.
Even from behind bars, the former cricket star has proved a powerful player in Pakistan politics. During elections in February his party, which had been banned from standing and was forced to run candidates as independents, emerged as the single largest bloc.
However, they fell short of a majority and their rivals united to form a new government.
The PTI has called for election results to be overturned because they say the vote was rigged, a claim disputed by the government.