The decision was taken to ensure the safety of students and staff amid the unrest, according to the deputy commissioner.

Educational institutions were also closed in the twin cities today (Monday) to maintain law and order situation amid the PTI protest.

The PTI protesters entered the federal capital on Tuesday evening, with a heavy contingent of police deployed in the city to ensure order.

Authorities have enforced a security lockdown for the last two days to block the protesters, whom Khan has called on to march on parliament for a sit-in demonstration, while highways into the city have been barricaded.

The government has used shipping containers to block major roads and streets in Islamabad, most of them patrolled by large contingents of police and paramilitary personnel in riot gear.

Officials and witnesses said all public transport between cities and terminals has also been shut down in the eastern province of Punjab to keep away the protesters, led by members of PTI.