A hardline Islamist group which has been blocking a key highway near here in Pakistan for 19 days clashed with the police on Sunday, while the Army took up positions in government buildings.
Sunday's violence comes a day after a failed police operation to disperse the demonstrators caused the deaths of 10 people and injured hundreds, reports Efe news.
"The protestors today threw stones at police and burned some motorbikes belonging to the police," an Islamabad police spokesperson said.
Another police official who did not wish to be named told Efe that the demonstrators had also torched a police checkpost and a police car.
The clashes followed the police's failed attempts at clearing the protest by followers of cleric Khadim Hussain Rizvi of the Tehreek-e-Labaik party.
They are demanding the resignation of Justice Minister Zahid Hamid over an amendment to an electoral law approved by Parliament which removed an oath public servants had to take before assuming office, reiterating their belief in Mohammed as the last prophet of Islam.
Following massive protests by hardline Islamists, who consider the amendment an act of blasphemy, Parliament reinstated the oath and Hamid issued a video in an attempt to appease the protesters.
At least 10 people were killed and over 250 injured in clashes on Saturday.
Meanwhile, soldiers began to take up positions in government buildings in Islamabad's Red Zone, where the country's main state institutions are located, including the Prime Minister's Office and the Supreme Court.
The military said details still needed to be clarified before troops are deployed to subdue the protest as ordered by the Interior Ministry on Saturday night.
In a statement, the Army said the police "have not been optimally utilized to its full capacity" and cited a court order prohibiting the use of firearms to disperse the protest.
Zubair Ahmed, a spokesperson of the Tehreek-e-Labaik Pakistan, said the protest would not be called off until the demands of the protesters were met.