The protesters, who before Saturday numbered some 2,000 people, are demanding that federal law minister Zahid Hamid resign over a hastily-abandoned amendment to the oath that election candidates must swear. But later violence has led to injuries to as many as 200 people according to hospitals in Islamabad and Rawalpindi.
Interior Minister Ahsan Iqbal told Reuters in a message on Saturday night that the government had "requisitioned" the military assistance "for law and order duty according to the constitution". Furthermore, the operation was initiated over the orders of the Islamabad High Court.
More than 8,000 personnel of police and paramilitary Rangers and Frontier Constablary launched the crackdown to clear Faizabad interchange linking Islamabad with garrison city of Rawalpindi and the only global airport of the capital.
So far one police official was martyred in I-8 Sector during the clashes while almost 200 persons of both sides had been injured.
They also pelted stones on the security personnel who used batons and teargas shells to disperse them. The list of those injured includes 111 police or other security forces, Dr. Tahir Nadeem, a physician at Pakistani Institute of Medical Services told Al Jazeera.
Jamaat-e-Islami chief Sirajul Haq said the government's crackdown had further aggravated the situation, adding, the government should have engaged the protesters in negotiations to resolve the standoff peacefully.
In Islamabad, thousands of security officials were deployed to break up the protests.
Policeman fires at protesters
In an unprecedented move, Pakistan Electronic Media Regulatory Authority ordered all private television channels to go off air for airing a live feed of the police action on the protesters.
Protesters attacked the house of federal law minister Zahid Hamid in Pasroor area of Sialkot district of Punjab but no one was injured as the minister and his family were not present inside.
Earlier in the day, a man was reported dead in a firing incident outside the residence of former interior minister Chaudhry Nisar.
They shattered windows and damaged furniture.
Pointing out the government's inefficiency in handling the whole fiasco, Shujaat said that it was the prime minister's job to negotiate with the protesters, but he was sitting in Lahore taking instructions from Nawaz Sharif.