Pakistani security forces fired shots in the air on Tuesday to quell supporters of a populist Muslim cleric calling for the resignation of the beleaguered government while the interior minister dismissed his demands as unconstitutional.
Sufi cleric Muhammad Tahirul Qadri, believed to be backed by Pakistan's powerful military, has brought tens of thousands of followers to the capital Islamabad to demand the resignation of top political leaders in the civilian government and electoral reforms to stamp out corruption.
"We will not accept Qadri's pressure because his demands are unconstitutional," Interior Minister Rehman Malik told local television channels shortly after security forces fired in the air and used tear gas to try and control protesters backing the cleric. The rally began on Monday and many of the protesters had stayed on the streets overnight.
Live television coverage showed forces firing in the air - a serious escalation in attempts to disperse crowds - while supporters of the cleric hurled stones at them.
A spokesman for Qadri said his supporters had prevented government forces from arresting him. The cleric recently returned home from Canada to lead a call for reforms that have made him an instant hit among Pakistanis disillusioned with the state.
The spokesman said six supporters of the cleric were wounded.
Qadri, who says elections scheduled for this spring should be delayed indefinitely until Pakistan's endemic corruption is rooted out, may not pose any immediate threat to the U.S.-backed civilian government, but his protest is the latest in a series of challenges for the administration.
Tens of thousands of Pakistani Shi'ite Muslims began burying the victims of a sectarian attack in a mass grave on Monday, ending an extraordinary three-day protest over one of the worst sectarian attacks in the country's history.
People from Shi'ite Hazara community had been holding vigil next to the bodies of the 96 people killed in Thursday's bombings in the city of Quetta to demand better protection from a rising tide of such attacks. The Shi'ite leaders only agreed to hold the burials after Prime Minister Raja Pervez Ashraf travelled to the provincial capital and agreed to some of their demands.
The government is also struggling to control Taliban insurgents based near the border with Afghanistan. Last week, the army became embroiled in another low-level skirmish with old enemy India along a ceasefire line dividing the disputed territory of Kashmir.
Qadri's campaign has divided Pakistanis. Some hold him up as a champion of reform, others see him as a possible stooge of the military, which has a history of coups and interfering in elections.
But he has suddenly emerged as a wildcard in the run-up to elections while the government is under fire for failing to tackle the Taliban insurgency, ease crippling power cuts and eradicate widespread poverty.
Qadri has fired up mostly middle and lower class Pakistanis who have gathered in central Islamabad's business district near parliament, and highlighted growing frustrations with the ruling Pakistan Peoples' Party (PPP).
His platform hinges on a demand that the judiciary bars corrupt politicians from running for office and that the army plays a possible role in the formation of a caretaker government which is due to manage the run-up to elections this spring.
The elections, if they proceed on time, could cement Pakistan's transition from military rule by marking the first time a civilian-led government has completed a five-year term and handed over power at the ballot box.
So Pakistan's current civilian leaders will be reluctant to step down even if Qadri gathers more momentum.
Few believe Pakistan's military has the appetite for another coup, especially since the Supreme Court has been standing up to the generals.
But the army would be happy to see figures like Qadri highlight the government's flaws, and perhaps play a behind-the-scenes role supporting him, analysts say. The military denies backing Qadri.
Qadri denies any relationship with the military but his insistence that the army might play a useful consultative role in the formation of a caretaker government has raised suspicions.