Tear gas shells, burnt tyres and vehicles litter the roads in Lahore's Zaman Park area which has turned into a battleground after supporters of Imran Khan engaged in pitched battles lasting over 11 hours with police personnel to stop them from arresting the ousted Pakistan premier, resulting in injuries to dozens of policemen.

Pakistan Tehreek-e-Insaf (PTI) workers and police clashed on Tuesday in Lahore's Zaman Park area after a contingent of the Islamabad police, along with armoured vehicles, reached party chief Khan's Lahore home to arrest him after a non-bailable warrant was issued in the ongoing Toshakhana (gift depository) case against him.

"Clearly 'arrest' claim was mere drama because real intent is to abduct & assassinate. From tear gas & water cannons, they have now resorted to live firing. I signed a surety bond last evening, but the DIG refused to even entertain it. There is no doubt of their mala fide intent," Khan tweeted on Wednesday.

The police, with their riot gear on and backed by Rangers, closed in on 70-year-old Khan's home in order to comply with the court orders to arrest him in the Toshakhana case.

Fearing the worst, various PTI leaders — including Khan himself — appealed to party workers to rush to Zaman Park, where they served as human shields and stood between Khan's residence and the police.

The police fired tear gas shells but were met with resistance and found PTI workers undeterred.

"After our workers & leadership faced police onslaught since yesterday morning of tear gas, cannons with chemical water, rubber bullets & live bullets this morning; we now have Rangers taking over & are now in direct confrontation with the people," Khan tweeted.

"My question to the Establishment, to those who claim they are 'neutral': Is this your idea of neutrality, Rangers directly confronting unarmed protestors & ldrship of largest pol party when their ldr is facing an illegal warrant & case already in court & when govt of crooks trying to abduct & possibly murder him?" he wrote on Wednesday.

For more than 11 hours, PTI workers engaged capital police in pitched battles that continued late into the night.

As night fell in Lahore, the PTI workers had gained the upper hand — not only had it opened more fronts across the city, the influx of a large number of supporters into Zaman Park forced security men to retreat. By midnight, police had suffered around 30 casualties, the Dawn newspaper reported on Wednesday.

At a late-night meeting summoned by the Punjab interim chief minister Mohsin Naqvi to take stock of the security situation in the provincial capital, it was decided to make another bid to detain the PTI chief and wrap up the operation before the morning.

In order to set the plan in motion, fresh units of police and Rangers took positions on The Mall in the early hours of Wednesday, the report said.

This is the second time in less than 10 days that the police have arrived at Zaman Park to apprehend the deposed prime minister.

In a conversation with the BBC, Khan said that the police came "all of a sudden" to arrest him without informing him.

"We saw on the news that the police were coming to arrest me," he said.

"I am all mentally prepared that I am going to spend my night in a cell and I don't know how many nights. I am all prepared for that. But I think they are determined [this time] and they want me behind bars," he said, according to Geo News.

In a late-night tweet, PTI leader Asad Umar said the president of the Lahore High Court Bar Association had assured that Khan would appear in the court on March 18.

In light of the undertaking, there was “no justification” for the police operation, he added.

Khan, in a video message on Tuesday, asked his supporters to "come out" to fight for real freedom and continue the struggle even if he is killed or arrested. "They (the government) think that after my arrest, the nation will fall asleep. You have to prove them wrong," he said in the video.

"God has given me everything, and I am fighting this battle for you. I have been fighting this battle all my life, and I will continue to do so.

"If something happens to me and I am sent to jail or if I am killed, you have to prove that you will struggle without Imran Khan and not accept the slavery of these thieves and of the one person who has been making decisions for the country," he said.

The standoff in Zaman Park has triggered protests across the country, and several cities saw protests by PTI workers.

In Islamabad, at least four policemen were injured and over two dozen supporters of the former ruling were detained after protests erupted in several parts of the federal capital, resulting in logjams across the city.

A series of organised and sporadic protests broke out in Karachi with Pakistan Tehreek-e-Insaf workers blocking roads and disrupting traffic in several areas of the city.

Soon after Khan's speech, protests broke out also in Peshawar, Faisalabad, Sargodha, Vehari, Quetta, and Mianwali.

The PTI has declared that it would not let law enforcement agencies arrest Khan as it fears he may be given poison in jail.

Khan has been in the crosshairs for buying gifts, including an expensive Graff wristwatch he had received as the premier at a discounted price from the state depository called Toshakhana and selling them for profit.

On Monday, the Lahore police booked Khan in a case related to the killing of the PTI worker - Ali Bilal alias Zille Shah - in a road accident.

Earlier, the Lahore police had registered an FIR against Khan and 400 others for the murder of Shah.

This is the 81st FIR against Khan since the PML-N-led federal coalition came into power 11 months ago after toppling his government through a no-confidence motion.

Khan was ousted from power in April last year after losing a no-confidence vote, which he alleged was part of a US-led conspiracy targeting him because of his independent foreign policy decisions on Russia, China and Afghanistan.

Since his ouster, Khan has been asking for early elections to oust what he termed an "imported government" led by prime minister Shehbaz Sharif.

Sharif has maintained that elections will be held later this year once the parliament completes its five-year tenure.