Pakistan has announced a ban on demonstrations in the capital after recent rallies by Islamic extremists turned violent and led to the destruction of property.

Interior Minister Chaudhry Nisar Ali Khan announced the ban at a news conference Monday, saying it will not extend to other parts of the country.

The move came less than two weeks after tens of thousands of radical Islamists descended on Islamabad to protest against the execution of a policeman who had assassinated a secular governor over his opposition to the country's harsh blasphemy laws.

Opposition leader Imran Khan vowed Sunday to hold a rally in the city of Lahore if Prime Minister Nawaz Sharif does not resign over documents leaked from a Panama-based law firm that Khan says link Sharif's family to offshore accounts.