Pakistan's government has called for troops to be deployed in the capital, Islamabad, after violence broke out during protests by Islamists.
Pakistani protesters throw rocks toward riot policemen during a clash in Islamabad Photo: AFP
About 200 people were injured when security forces tried to disperse an Islamist sit-in at the Faizabad Interchange - a key highway.
Several deaths have been reported.
The protesters have been blocking the highway for several weeks, demanding the sacking of Law Minister Zahid Hamid, who they accuse of blasphemy.
Pakistani media report that demonstrators also broke into the minister's residence in Punjab province. Mr Hamid and his family were not in the building.
The protests have spread to other cities, including the southern port of Karachi.
The Pakistani government authorised the deployment of the army in Islamabad on Saturday evening, local time.
The interior minister said the order was issued at the request of the city authorities, who were not able to clear the sit-in.
Earlier, security forces used tear gas and rubber bullets to try to disperse the demonstrators, Pakistani media report, but were met with rocks and tear gas shells.
About 8500 elite police and paramilitary forces took part in the operation to clear the Faizabad Interchange. The crackdown was later suspended.
Protesters said four of their activists were killed, but police said there were no deaths, Reuters reports.
However officials are quoted in other reports confirming that several people were killed. Many of those injured are security personnel.
The request for the military deployment came after hundreds more demonstrators turned up unexpectedly, forcing the police to retreat.
There was no immediate comment from the Pakistani military.
The protesting Islamists, from the hardline Tehreek-i-Labaik Ya Rasool Allah Party, want the law minister to be sacked for omitting a reference to the Prophet Muhammad in a new version of the electoral oath.
The minister has since apologised, saying it was a clerical error.
-BBC
