Protests also broke out in Lahore and the southern port city of Karachi, local media reported. The police was acting on a court order which directed that the protests be cleared.
On Friday, Islamabad High Court (IHC) called the protest an act of terrorism and ordered the government to remove the protestors.
The protesters, who before Saturday numbered some 2,000 people, are demanding that Pakistan's law minister Zahid Hamid resign over a hastily-abandoned amendment to the oath that election candidates must swear.
Earlier, the Islamabad police, with the help of Frontier Constabulary personnel and other law enforcement agencies, launched an operation against protesters after the last of a long series of deadlines lapsed on Saturday morning without response from the agitators.
The security forces fired tear gas and rubber bullets as the protesters continued to block the roads to Islamabad.
Pakistan's media regulator barred local TV channels from broadcasting live images from the scene, though protesters were still using Facebook Live and other social media.
Army chief General Qamar Javed Bajwa talked to Prime Minister Shahid Khaqan Abbasi and asked him for a peaceful solution to the problem.
The clashes started after police officials surrounded the protesters at the sit-in area in Faizabad, on the road which connects Rawalpindi to Islamabad.
Television footage showed a police vehicle on fire, heavy curtains of smoke and fires burning in the streets as officers in heavy riot gear advanced.
But protest leaders were adamant and refused to clear the intersection unless the law minister resigned. When police used tear gas to disperse them amid the traffic rush hours, protesters threw stones wounding 20 people, including two journalists.
Later in the day, security forces appeared to face difficulty clearing the crucial intersection as more and more supporters joined protesters at the site, a bridge between the capital and Rawalpindi. But later violence has led to injuries to as many as 200 people according to hospitals in Islamabad and Rawalpindi.
They reported that police arrested around 150 protesters, some with knives and pistols. "First, they stole our mobiles and wallets, and then they beat us mercilessly with sticks and their fists", he said. Hamid's residence in Sialkot was also attacked.
Faizabad sit-in was causing a chaotic situation in the capital city. The interior minister said the protesters had also "contacted India", according to a report in the newspaper.
However, the publication turned down the President's claims, saying the award victor will only be declared on December 6. Quoting Trump's tweet Stengel, Stengel asserted,"They just wanted a photo shoot".
However, on a visit to Leeds, the Prime Minister offered praise for Mr Hammond, stating that he had done "a very good job". Director Mr Johnson added: "That assumes no recessions for the next half century".
Lily Hinz said the unusual sound detected underwater could not be attributed to a naturally occurring noise in the ocean. Navy said it had deployed unmanned underwater vehicles, or "mini-subs" equipped with sonar, to join the search.
Whitman said she is not sure of her next step, but that any next CEO position would have to be "exactly the right opportunity". At one point, she was even reported to be taking Uber's CEO role but later confirmed she had no interest.
In the weeks leading up to the 2016 USA election, Facebook shut down 5.8 million fake accounts in the United States. The web page will show only a list of accounts, not the posts or ads affiliated with them, according to a mock-up.
The site attempts to document whether the president played during such visits, ranking them "yes", "likely" or "probably not". Trump, the first lady, and their son Barron are now staying at the Mar-a-Lago resort in Palm Beach, Florida, until Sunday.
The University of Florida had been pursuing Kelly, but the Gators made a decision to move in another direction this week. His contract is for five years and $23.3 million, with a $9 million reciprocal buyout, according to school officials.
Providing a list of all the individual Russian interference posts a user saw or interacted with could be more useful. It will track activity between January 2015 and August 2017, and be available through the Facebook Help Center.