Rawalpindi/ISLAMABAD - Police clashed with opposition supporters in Rawalpindi on Friday, arresting dozens ahead of a planned protest by PTI leader Imran Khan aimed at unseating the government.

Police charged stone-throwing protesters with batons and fired tear gas at the supporters of Pakistan Tehreek-e-Insaf and Awami Muslim League who had come out onto the streets to demonstrate against arrests made the previous night after authorities banned all public gatherings in the capital for two months.

Municipal workers meanwhile used shipping containers to block major roads leading from Rawalpindi to Islamabad, where Khan has vowed to lead a demonstration on November 2 to demand Prime Minister Nawaz Sharif step down over revelations made in the Panama Papers that his family have offshore bank accounts.

The battles began when police, supervised by City Police Officer Israr Ahmed Khan Abbasi, detained PTI MPA Ijaz Khan Jazzi along with 17 workers of AML and PTI.

Taking positions on bridge of the Metro Bus stop, police targeted the violent protesters who kept throwing stones from four positions.

Reportedly, the protesters set a container on fire at Committee Chowk and attacked a police mobile van outside Green Palace Hotel, smashing its windowpanes. The intense use of teargas shells by riot police affected a large number of the residents. Some cops also fainted due to massive shelling.

There was no immediate report of injuries and the violence eased as darkness fell.

The clashes and blockade caused a lot of troubles to area residents and commuters. The business centers and petrol pumps along Murree Road remained closed while public transport remained off the road.

A heavy contingent of police meanwhile surrounded Khan's house in Banni Gala, a leafy suburb of Islamabad, preventing him from leaving – though he has not been formally arrested.

Dozens of Khan's supporters also gathered around the house, chanting anti-government slogans calling for Sharif to resign.

Imran Khan later made a brief appearance in front of the media vowing he would not be deterred and would lead his protest as planned.

"As long as I am alive I won't sit idle until I hold Nawaz Sharif accountable. Throw me in prison, when I'm out I will start again," he said.

"Try stopping me if you can, you will be unable to stop a flood of people on November 2."

He said he had been placed "under almost house arrest" by scores of police officers stationed around his home. He said he had cancelled plans to attend a rally by a political ally – Sheikh Rashid - in Rawalpindi and urged supporters to instead focus on the mass protests on Wednesday.

"To all my activists, you have to prepare for Nov 2, you have to escape capture," he said.

Moments after Khan's appearance before the media, his supporters clashed with police, chanting slogans and pelting stones at police vehicles.

An AFP reporter at the scene said protesters damaged a number of vehicles, breaking windscreens and chanting "Go Nawaz Go". The police retaliated with tear gas, dispersing the demonstrators.

Sheikh Rashid, a Khan ally who heads his one-man Awami Muslim League (AML), cancelled the planned rally but joined his supporters in the streets of Rawalpindi.

TV footage showed the portly AML leader being ferried to the rally on the back of a motorbike through the side streets of Rawalpindi. He then climbed on top of a van, shook his fist in the air to supporters and dared police to arrest him.

Dozens of PTI protesters staged protests in Karachi, Lahore and some other cities demanding release of the detained activists.

Prime Minister Nawaz Sharif is under growing pressure from opposition parties over his children's offshore bank accounts, revealed in the Panama Papers leak.

The planned protest plan comes at a sensitive time for Sharif, with Pakistan's Supreme Court due to start hearing a case about the Panama Papers revelations on November 1.

The exact number of arrests of opposition supporters could not be confirmed, but a PTI spokesman said 43 workers were arrested on Thursday night were still in detention while others had been released. The party said that dozens of their activists had been arrested on Friday.

PTI cancelled a rally planned for Saturday in Islamabad.

Earlier, Islamabad Deputy Commissioner Mushtaq Ahmed said Khan's party would need official permission, in the form of a so-called "No Objection Certificate", to host any events, including Wednesday's shutdown strike.

"You need an NOC for anything - whether it's a media function or a marriage function. Even for a birthday party of more than five people, you need an NOC," he said.

Imran Khan had led a weeks-long occupation that paralysed the government quarter of Islamabad in 2014 after rejecting PML-N’s decisive election win. That protest sit-in, longest in country’s history, failed to achieve its objective as none of the key political players lend support to PTI cause.

This time Imran Khan has said their next week's protests would bring a million people onto the streets and sit-ins would force the closure of schools, public offices and the main international airport.

The ruling party has dismissed Khan's shutdown plan as a desperate move by a politician whose popularity is waning ahead of the next general election, likely to be held in May 2018.

Earlier in the day, Islamabad District administration wrote a letter to the PTI chairperson in the wake of the IHC order to tell him that “the lockdown is not permissible” as it would deprive the citizens of their fundamental rights and is a “serious threat to public peace and tranquility”.

The letter, written by the district magistrate was delivered to Imran Khan at his residence by a city magistrate, said that therefore necessary restrictions (Section 144 CrPC) have been imposed. The district administration however offered PTI a designated place, Democracy and Speech Corner, for a ‘lawful’ gathering.