Police officers fire tear gas to disperse the supporters of Imran Khan's party during a protest in Islamabad on Saturday. AP / Reuters

Chief Minister Ali Amin Gandapur was leading a convoy of Imran Khan supporters into Islamabad, which clashed with police officers on Friday and Saturday.

He was detained by paramilitary and police forces after he arrived at the official residence of the Khyber Pakhtunkhwa chief minister in Islamabad, Imran's spokesperson Zulfikar Bukhari told journalists.

Leaders of Imran's Pakistan Tehrik-e-Insaf party earlier said Gandapur had been arrested by police. They later clarified that he had been taken into custody but not formally arrested.

Also on Saturday, cellphone services remained suspended in Islamabad as it entered a second day of a lockdown aimed at thwarting rallies in support of Imran Khan. He is in prison on multiple charges.

Shipping containers blocked off the city’s entry and exit points, but videos from Imran Khan’s PTI party showed supporters piled into vehicles and attempted to head toward Islamabad.

Earlier, the chief minister of Khyber Pakhtunkhwa province and others in the convoy worked throughout the night to remove shipping containers from the road, according to the party.

Clashes broke out between Imran Khan supporters and security forces in D-Chowk, which is close to several key government buildings including Parliament and the Supreme Court. The PTI also said it planned to hold a rally in Lahore.