The Islamabad district administration imposed Section 144 in the city ahead of a no-confidence motion scheduled against Pakistan Prime Minister Imran Khan in the National Assembly on Sunday, 3 April.
Khan faces a tough fight for his political survival as the odds are stacked against him in Sunday's all-important vote.
Khan's party, the Pakistan Tehreek-e-Insaf (PTI), lost the majority in the House as its primary coalition partner, the Muttahida Qaumi Movement- Pakistan (MQM-P) – abandoned the government on 30 March and signed a deal with the opposition Pakistan Peoples Party (PPP).
With this development, the ruling coalition was down to 164 lawmakers in the National Assembly, while the Opposition now has 177 members.
However, the embattled PM said on 31 March that he would not resign ahead of the no-confidence vote.
Don't Resort to Unconstitutional Means During Vote: Pak Rights Body
Meanwhile, the Human Rights Commission of Pakistan (HRCP) on Sunday warned the government against indulging in unconstitutional measures during the vote on Sunday.
"HRCP strongly warns the federal government to refrain from resorting to any unconstitutional measures to prevent members of Parliament from attending Sunday's National Assembly session at which a no-confidence motion against the Prime Minister is expected to be held," the rights body tweeted.
It also said that state institutions had no right to interfere in parliamentary processes, and condemned threats against journalists, emphasising that there must be unimpeded freedom of press to report on proceedings.
"The media must remain free to report and analyse the proceedings fairly and independently. We also condemn threats to journalists who have commented – as is their job – on the questionable behavior of Prime Minister Imran Khan and his government in recent days," it added.
PTI Lawmakers will Resort to Violence: Pak Journalist Quotes Sources
The HRCP's warning comes amid reports of plans by PTI lawmakers to resort to violence to prevent members of the Opposition from voting.
During a programme on Geo News on Saturday, journalist Hamid Mir said that as per information from sources, PTI lawmakers would attempt to stop members of the Opposition from leaving Parliament Lodges and entering the Assembly, ANI reported.
Mir added that regardless of whether Opposition members try to enter the House or remain outside, "they will be beaten".
Punjab Governor Removed Hours Before Vote
Meanwhile, Chaudhry Mohammad Sarwar, the governor of Pakistan's Punjab province, was removed from his post hours before the vote, Information Minister Fawad Chaudhry said in a tweet in Urdu.
It was, however, not made clear why Sarwar had been asked to resign.
A member of Pakistan's Opposition also moved a motion for the removal of the National Assembly Speaker Asad Qaiser ahead of the no-trust motion against Khan.
More than 100 members of Opposition parties signed the no-confidence motion against Qaiser.
A day ahead of the vote, PM Khan said that "foreign conspirators are auctioning Pakistani politicians like scapegoats".
He also accused the United States (US) of planning to overthrow his government with the help of Pakistani politicians who, the PM claimed, were sold for $15-20 million.
Earlier, the embattled PM had urged legislators from his party to abstain from voting on the no-confidence motion brought against him, or miss the session of the National Assembly on the day the motion will be voted on in the House.
Khan needs 172 votes in the 342-member House to defeat the motion against his government.
If he loses the motion, the tradition of a Pakistani PM never completing a full five-year term in office will continue.
(With inputs from ANI.)