Supporters of Imran Khan climb on container barricades as they participate during a Freedom March to the parliament house in Islamabad on Tuesday.

Reuters/Islamabad

Tens of thousands of protesters used a crane and bolt cutters to force their way past a barricade of shipping containers in the Pakistani capital on Tuesday as they marched on parliament to try press the prime minister to resign.

Thousands of Pakistani riot police and paramilitaries had used the containers and barbed wire to seal the diplomatic and political zone of the capital before the march began.

Police have been instructed to try to avoid violence. They did not intervene as protesters moved the outermost of a ring of barricades. Police in the outer ring of security have sticks, not guns. Some are armed with tear gas and rubber bullets.

The protests are led by former international cricketer Imran Khan, head of the country's third-largest political party, and cleric Tahir ul-Qadri, who controls a network of Islamic schools and charities.

Hours before the marchers set off, the interior minister announced that soldiers would be deployed to stop the protesters.

The announcement was intended to send a message to the coup-prone country that the protests do not have military backing. It also underscored how the domestic opposition has forced the fledgling civilian government to rely on the country's powerful army, despite deep mistrust between the two institutions.

The protests have piled extra pressure on the 15-month-old government as it struggles to overcome high unemployment, daily power cuts and a Taliban insurgency. The showdown has also raised broader questions over the stability of Pakistan, a nuclear-armed nation of 180mn people.

Khan and Qadri both want Prime Minister Nawaz Sharif to resign. Khan accuses him of rigging last year's polls. Qadri accuses him of corruption. Police estimate the two protest leaders have around 55,000 supporters between them.

Both Khan and Qadri have been holding protest rallies in the capital since Friday with government permission. But they have been banned from the "Red Zone", which houses many Western embassies, parliament and the office and home of Sharif.

Their protests have so far remained separate because the two have different supporters and different plans for what should happen if Sharif steps down.

But on Tuesday, Qadri said his supporters would march on parliament, a day after Khan asked his supporters to do the same.

"The people's parliament ... have decided to do their sit in in front of parliament," Qadri announced on Tuesday evening, referring to his protesters, to approving roars from the crowd.

Most of Khan's supporters are young men. Qadri's supporters are seen as more disciplined and determined; there are many families among them. All the men have sticks; brigades of youths also have goggles and masks to deal with teargas.

The Red Zone is sealed off with shipping containers and barbed wire and flooded with riot police and paramilitaries.

Khan said any violence would be the fault of the prime minister, as his female supporters scattered baskets of rose petals over bemused police in body armour.

"If police try to stop us and there is violence, Nawaz I will not spare you, I will come after you and put you in jail," Khan said.

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