A showdown was set Sunday as a coalition of Pakistani religious parties planned to defy a government ban and hold another rally in the capital to protest cartoons of the Prophet Muhammad.
The government on Saturday warned radical Islamic groups against holding the rally, fearing that it would spark more violence after at least five people died in riots across the country over the past week.
Pakistani intelligence officials have said militants from outlawed extremist groups have been stirring up the violence. Authorities have banned demonstrations in several cities in the country's east, where riots turned deadly last week.
But one of the rally's organizers said his group would defy the order and go ahead with a protest on Sunday.
"Our supporters are being arrested by police in raids at their homes, but we will hold the rally as planned," Mian Mohammad Aslam, a lawmaker with a coalition of six religious parties, said.