Ousted prime minister of Pakistan Imran Khan on Thursday gave a six-day deadline to the Shehbaz Sharif government for dissolving provincial assemblies and announcing fresh general elections, warning that if the "imported government" failed to do so, he would return to the capital with the "entire nation".

Addressing a rally of thousands of protesters of the 'Azadi March' at Jinnah Avenue here on Thursday morning, Khan lashed out at the government for using tactics like raids and arrests to stop his party's march, even as he thanked the Supreme Court (SC) for taking notice of the matter.

"Government has tried every method to crush our Azadi March, they used teargas on peaceful protest, our homes were raided and privacy of the homes were violated, however, I have seen the nation free itself of fear of slavery," he said.

"My message for the imported government is to dissolve assemblies and announce elections, otherwise, I will come back again to Islamabad after six days," he was quoted as saying by the Geo News.

Noting that there was a "huge responsibility" on the Supreme Court judges, Khan asked where in a democracy peaceful protests were not allowed and demonstrators had to face tear-gas shelling, police raids and arrests.

"I had decided that I will sit here until the government dissolves assemblies and announces elections, but of what I have seen in the past 24 hours, they (govt) are taking the nation towards anarchy," he said, claiming that the government was also trying to create a divide between the nation and police.

Khan said the government would be happy if he staged a sit-in in Islamabad as it would lead to clashes between the people and police and the army, the Dawn newspaper reported.

He claimed that five protesters from his Pakistan Tehreek-e-Insaf (PTI) were killed in clashes after the party's march, saying that one had fallen off the Attock bridge amid tear-gas shelling and the other was pushed into the Ravi river.

He said he had also received information that three were killed in Karachi.

"I am again asking the judiciary to save your FIA (Federal Investigation Agency). In the future, no FIA officer will investigate the powerful if he will meet the same end as Dr Rizwan and Asghar," he said.

The PTI chief said he and the entire nation were looking towards the judiciary after what had happened during the past 48 hours.

He said he had reached Islamabad after 30 hours of travelling from Khyber Pakhtunkhwa. Following his six-day deadline announcement, ex-premier Khan left for Bani Gala, leaving behind his supporters who marched for hours in anticipation of a major public gathering and sit-in.

Khan had entered Islamabad in the early hours of Thursday and marched towards D-Chowk, while the federal government authorised the deployment of the army in the Red Zone to "protect important government buildings".

Interior Minister Rana Sanaullah tweeted a notification saying the government was "pleased to authorise the deployment" of the army in the Red Zone under Article 245 of the Constitution.

Among the buildings that will be protected are the Supreme Court, Parliament House, Prime Minister House, Presidency, Pakistan Secretariat and Diplomatic enclaves," the notification said.

Khan, who was ousted from power last month through a no-trust vote, had apparently lost support of the Army after he refused to endorse the appointment of the ISI spy agency chief last year.

He has been claiming that the no-trust motion against him was the result of a foreign conspiracy because his independent foreign policy and funds were being channelled from abroad to oust him from power. He has named the US as the country behind the conspiracy, a charge denied by Washington.

Addressing his supporters in Khyber-Pakhtunkhwa on Wednesday, Khan earlier said the "thieves and the servants of America were ruling in Islamabad".

Prime Minister Sharif's coalition government initially allowed the protest, but on Tuesday refused to give permission, fearing violence and lawlessness in the wake of the march.

Earlier on Wednesday, police fired tear gas and chased Khan's supporters who hurled stones near Punjab's capital Lahore, leaving several persons from sides injured. The clashes between the police and Khan's supporters were also reported at several places.