Pakistani Muslims shout slogans on the outskirts of Islamabad on March 1, as they gather outside the tomb of Mumtaz Qadri, who was hanged in February 2016 for the murder of a governor who criticized Pakistan's blasphemy law. (AAMIR QURESHI/Agence France-Presse/Getty Images)

Thousands of religious protesters converged on the capital Saturday in a growing confrontation with the Pakistani government over official attempts to amend a law that requires all political candidates to affirm their belief that Muhammad, who lived in the 7th century, was Islam’s final prophet. More than 95 percent of Pakistanis are Muslim.

The demonstrators were stopped by security forces and shipping containers placed across major roads, halting most traffic in the capital region for much of the day and preventing office workers, students and other commuters from traveling between Islamabad and the nearby garrison city of Rawalpindi. They remained there as night fell and vowed to stay indefinitely.

The crusade to “defend the honor of the prophet” is being led by a fringe Muslim group called the Movement in Service of the Messenger of God. It is widely seen as an attempt to arouse public antipathy to Ahmadis, a small religious minority in Pakistan whose followers claim to be Muslim but who also follow a 19th-century prophet. Ahmadis were declared non-Muslim in 1974.

The emotional protests, which began two weeks ago and have grown since, are also viewed as a direct challenge to the authority of the federal government, which has been weakened since former Prime Minister Nawaz Sharif was ousted by the Supreme Court. The Messenger of God movement, once seen as a purely religious fringe group, has begun running candidates for parliament in the past two months.

The protest leaders have demanded that the federal law minister be fired, charging that he was behind an effort to weaken the electoral law affirming the prophet’s “finality.” They declared Saturday that they will not leave their protest site at the main entrance to the capital until the minister is punished. Pakistani media reports said they also threatened to attack the homes of some government officials.

The government has made no public statements about the protesters or their demands in the past several days, but officials apologized last week about what they called a “clerical error” in the electoral law amendment process and restored the original oath that all candidates must take affirming the prophet’s finality.

“We are not afraid of prison. We are ready to die for our prophet,” Allama Khadim Hussain Rizvi, leader of the Messenger of God group, declared to a large, emotionally charged crowd from atop a shipping container. “We are here to stay until our demands are accepted, and our first demand is that the law minister be [fired].”

Rizvi asserted that the legislative change was an attempt to “create chaos” among the Muslim faithful. “The government must reveal who did this conspiracy against our religion . . . who was behind the law minister and who wanted to please the Ahmadis,” he said. No serious violence was reported, but rallies were also held in Karachi and Lahore, and some arrests were made.

Some analysts and political figures have asserted that the “deep state,” a euphemism for the powerful security establishment and its allies in the government bureaucracy, is encouraging the protesters to besiege the capital in a “simmering coup” against the government headed by Prime Minister Shahid Khaqan Abbasi, who was picked by Sharif to run the country until elections next year.

There have been similar assertions that such forces were supporting the recent political candidacies of figures from the Messenger of God movement and another radical religious group. Sharif was overthrown previously by the army in 1999, but current military leaders have repeatedly asserted that they represent no threat to democracy.

The Messenger of God movement was formed in 2015 to defend the country’s harsh blasphemy laws, and it built a following around the case of Mumtaz Qadri, a man who assassinated a provincial governor for raising questions about a blasphemy case. The group reveres Qadri, who was hanged last year, as a hero and a martyr to Islam.

Constable reported from Kabul.