Pakistan's powerful army called on the government and protesters to resolve their differences peacefully on Sunday night but ominously warned it was "committed to playing its part in ensuring security of the state", after clashes left three dead.
The meeting of top generals, brought forward a day, came after violence broke out on Saturday night when thousands of supporters of politician Imran Khan and firebrand cleric Tahir-ul-Qadri tried to storm Prime Minister Nawaz Sharif's house, demanding his resignation.
Opposition groups marched to the capital on August 15 in a bid to topple Sharif's government, triggering a crisis that has raised the spectre of military intervention in a country that has been ruled for half its history by the army.
The fighting continued Sunday between police in riot gear and a few hundred protesters, many of whom came armed with batons and slingshots loaded with marbles.
Shipping containers were set ablaze, several vehicles were torched, and hundreds of tear gas canisters lay strewn on the ground on Islamabad's normally pristine Constitution Avenue after almost 24 hours of battle.
By nightfall on Sunday protesters were preparing for fresh clashes, breaking up the road to use chunks as missiles and assembling crude gas masks from cloth and plastic bottles.
Following a meeting at army headquarters in the garrison city of Rawalpindi, the military voiced support for democracy -- but also stressed its own role in maintaining security.
"While reaffirming support to democracy, the conference reviewed with serious concern, the existing political crisis and the violent turn it has taken, resulting in large scale injuries and loss of lives," the statement said.
"It was once again reiterated that the situation should be resolved politically without wasting any time and without recourse to violent means," it added.
"(The) army remains committed to playing its part in ensuring security of the state and will never fall short of meeting national aspirations."
The statement opened with a backing for the government but ended on a hawkish note -- which a senior government official said reflected differing views within the army's top brass.
"There is always a difference of opinion when 10 to 15 people are sitting together. There are some who have stronger opinions and some who have softer opinions," the official told AFP, speaking on condition of anonymity.
Pakistan's last period of military rule ended in 2008. But the official said another coup remained "less likely".
"We have travelled this road for seven to eight years, so things have been tested the institutions are much stronger," he said.
"I hope and pray the system survives. There will be some losses but they will be recovered," he added, referring to the significant concessions that observers say the government will need to give the army if it is to survive.
Sharif has convened an extra-ordinary sitting of parliament on Tuesday to discuss the crisis, a cabinet minister told AFP.
Opposition leaders claim the 2013 election which swept Sharif to power was rigged, though local and foreign observers rated the polls as relatively fair and credible.
Speaking from the roof of a shipping container Sunday, Khan vowed to continue his protest "until our last breath", adding he would file murder charges against the prime minister over the violence.
The Pakistan Institute of Medical Sciences reported three deaths from the violence -- two men from injuries sustained in the fighting and another who died of a heart attack.
At least 481 injured people, including at least 118 women and 10 children, were rushed to the city's two major hospitals, according to officials. At least 92 police were among the wounded.
Outside the protest zone, small groups of protesters blocked the main expressway linking the city to the airport and forced traffic to a halt by putting tree branches and rocks on the road and pelting vehicles with stones.
A group of up to 15 teenage protesters armed with bamboo sticks and rocks attacked a vehicle carrying three United Nations staff members near parliament.
"Their vehicle was damaged but they escaped unhurt," a UN source told AFP.
In Lahore around 300 Khan supporters burnt tyres and attacked the Metro Bus service in the Model Town suburb where the prime minister has a private residence.
The protest leaders have drawn thousands to the streets of Islamabad, but their call has not mobilised mass support in a country of 180 million people.
But many of the protesters are now openly calling for the military to return to power.
"Last night, the police used tear gas and rubber bullet against us. Now we are waiting for the help of the army. We are hopeful. Insh'allah (God willing) the army will save us, they will do something for us," said a female protester in her twenties called Ammara.
Sharif, whose previous term as prime minister ended in a bloodless coup in 1999 by ex-ruler Musharraf, has vowed to stay on.