Eight people were killed yesterday when Pakistani riot police armed with assault rifles clashed with followers of a prominent preacher and anti-government critic in the eastern city of Lahore.
The clash, a rare act of political violence in Prime Minister Nawaz Sharif's home city, involved supporters of cleric Tahir-ul-Qadri who lives in Canada but is due to come to Pakistan next Monday.
He hopes to lead a "peaceful revolution" against the country's parliamentary democracy which he considers corrupt.
The religiously moderate cleric has a large following in Pakistan. But some analysts believe he is also supported by the country's powerful military establishment to keep civilian authorities in check.
Shahbaz Sharif, who is Nawaz's brother and also chief minister of the Punjab province of which Lahore is the capital, said eight people were killed and 97 others including 28 policemen were wounded.
He demanded a probe into the violence and offered to resign if he was found culpable.
"I am deeply saddened over the killings and I offer my sympathies to Tahir-ul-Qadri and the bereaved families," he said.
"If I am held responsible, I will immediately resign because I cannot even imagine using force against anyone and my past five years and previous tenures reflect that."
Police said the clashes began when they went to remove what they called illegal security barricades from the office of Qadri's Pakistan Awami Tehreek, in the city's Model Town suburb on Monday night.
"When police arrived to remove illegal encroachments, party workers started pelting stones and threw petrol bombs from the roof," said city police chief Chaudhry Shafiq.
Shafiq said the deaths resulted from "bullets fired by workers, not police".
Qadri is viewed as a religious moderate and has authored numerous books as well as a fatwa denouncing suicide bombs.
A Canadian citizen, he is something of a favourite on the international lecture circuit and has been a guest at the World Economic Forum in Davos.