NEW DELHI: Tension gripped many Pakistani cities on Wednesday as former prime Imran Khan's supporters faced roadblocks on their way to Islamabad for a massive protest.

Pakistani authorities took extraordinary measures such as using shipping containers and concrete blocks on highways to prevent thousands of people, who responded to Imran's call for the Azadi March (freedom march), from leaving major cities.

Many workers and leaders of Imran's Pakistan Tehreek-e-Insaf (PTI) were rounded up in Punjab province, according to information shared on social media by the former ruling party.

The government had on Tuesday decided not to allow the marchers to gather in the national capital, but a defiant Imran told his supporters that "everyone must break out of the grip of fear to achieve freedom."

Television footage showed marchers removing roadblocks and getting into tense standoffs with the police.

Imran led a large procession from Khyber Pakhtunkhwa (KPK) province.

Imran's destination was D-Chowk, the square outside the parliament building, and he was expected to enter the capital at night.

"We will remain in Islamabad till announcement of dates for dissolution of assemblies and elections are given," he said.

Meanwhile, the Supreme Court of Pakistan ordered the government and Imran's party to hold talks to de-escalate the situation, according to Pakistani media.

The court also ordered the government not to arrest Imran.

-- BERNAMA