Pakistan's national PTV channel, and its English-language PTV World service, was temporarily taken off air after protesters stormed its headquarters in central Islamabad.

Pakistani paramilitary forces later escorted the protesters out of the building and placed it under army protection.

There were no signs of violence and the news footage showed the protesters leaving the building peacefully.

Elsewhere in the capital, protesters wielding sticks and throwing stones marched on government buildings after weeks of demonstrations demanding Prime Minister Nawaz Sharif's resignation.

Protests led by Imran Khan and cleric Tahir ul-Qadri began last month and descended into deadly chaos on Saturday, with at least three people killed in clashes with police.

This morning, despite heavy rain, crowds of protesters fought running battles with retreating police forces after breaking the main gate into the Pakistan Secretariat area which houses government ministries as well as Mr Sharif's residence.

Although they fired occasional teargas canisters, police were seen retreating and showing restraint as protesters, many carrying wooden clubs, pushed closer to Mr Sharif's house.

It was not clear if he was at the residence.

Mr Sharif, who swept to office last year in Pakistan's first democratic transition of power, has refused to resign.

He is due to address both houses of parliament tomorrow in an apparent effort to show that he is firmly in control.

But even if he survives the crisis he is likely to remain significantly weakened for the rest of his tenure and sidelined by the army on key issues such as foreign policy and security.

As protesters charged towards police lines in the so-called red zone - home to the prime minister's house, parliament and many foreign embassies - security forces could be seen retreating, with police huddled in groups and avoiding direct confrontation.
Reflecting concern about security in the capital, all schools were closed today, the start of a new academic year.