Pakistan's government has called on the army to help clear a sit-in by Islamist hard-liners blockading the capital after police clashed with activists and religious protests spread to other cities.
Dozens of people were injured in Saturday's clashes, including many police, according to reports from hospitals. Protesters said four of their activists had been killed, but police said there had been no deaths.
By nightfall, protests spread to other main cities with activists brandishing sticks and attacking cars in some areas. New demonstrators had joined the camp in Faizabad, just outside Islamabad, in a stand-off with police,
Private TV stations were ordered off the air, with only state-run television broadcasting.
Activists from Tehreek-e-Labaik, a new hard-line Islamist political party, have blockaded the main road into the capital for two weeks, accusing the law minister of blasphemy against Islam and demanding his dismissal and arrest.
"We are in our thousands. We will not leave. We will fight until end," Tehreek-e-Labaik party spokesman Ejaz Ashrafi told Reuters by telephone from the scene.
Tehreek-e-Labaik is one of two new ultra-religious political movements that have risen up in recent months and seem set to play a major role in elections that must be held by summer next year, though they are unlikely to win a majority.
CHAOS AND "CONSPIRACY"
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".
The ruling party of former prime minister Nawaz Sharif - who was disqualified by the Supreme Court in July and is facing a corruption trial - has a fraught history with the military, which in 1999 launched a coup to oust Sharif from an earlier term.
Earlier in the day, Iqbal said the protests were part of a conspiracy to weaken the government, which is now run by Sharif's allies under a new prime minister, Shahid Khaqan Abbasi.
"There are attempts to create a chaos in (the) country," Iqbal said on state-run Pakistan TV.
"I have to say with regret that a political party that is giving its message to people based on a very sacred belief is being used in the conspiracy that is aimed at spreading anarchy in the country," Iqbal added, without saying who he considered responsible.
Pakistan's army chief on Saturday called on the civilian government to end the protest while "avoiding violence from both sides". Opposition leader Imran Khan called for early elections, saying the "incompetent and dithering" administration had allowed a breakdown of governance.
The clashes began on Saturday when police launched an operation involving some 4,000 officers to disperse around 1,000 activists and break up their camp, police official Saood Tirmizi told Reuters.
Television footage showed a police vehicle on fire, heavy curtains of smoke and fires burning in the streets as officers in heavy riot gear advanced. Protesters, some wearing gas masks, fought back in scattered battles across empty highways and surrounding neighbourhoods.
The protesters have paralysed daily life in the capital, and have defied court orders to disband.
Tehreek-e-Labaik blames the law minister, Zahid Hamid, for changes to an electoral law that changed a religious oath proclaiming Mohammad the last prophet of Islam to the words "I believe", a change the party says amounts to blasphemy.
The government put the issue down to a clerical error and swiftly changed the language back.
Tehreek-e-Laibak was born out of a protest movement lionizing Mumtaz Qadri, a bodyguard of the governor of Punjab province who gunned down his boss in 2011 over his call to reform strict blasphemy laws.
The party won a surprisingly strong 7.6 percent of the vote in a by-election in Peshawar last month.
MORE JOIN PROTESTS
The government had tried to negotiate an end to the sit-in, fearing violence during a crackdown similar to 2007, when clashes between authorities and supporters of a radical Islamabad mosque led to the deaths of more than 100 people.
Despite the police crackdown, the protesters were largely still in place by nightfall and Tehreek-e-Labaik leader Khadim Hussain Rizvi, a prominent cleric, remained at the site, party activist Mohammad Shafiq Ameeni said.
Four protesters had died in the police crackdown, he added.
By late afternoon, Tehreek-e-Labaik supporters were coming out on the streets in other Pakistani cities in support.
Police fired tear gas in Karachi, the southern port that is Pakistan's largest city, to try to disperse about 500 demonstrators near the airport.
Outside the northwestern city of Peshawar, about 300 protesters blocked the motorway to Islamabad and started attacking vehicles with stones and sticks.
In the eastern city of Lahore, party supporters blocked three roads into the city.