The clashes broke out late last night when the demonstrators who have laid siege to the heart of the Pakistani establishment, housing the Presidency, the National Assembly, the Supreme Court, the Prime Minister's Office, sought to storm Prime Minister Nawaz Sharif's residence nearby after breaking through the police barricade.
The violence continued throughout the night and subsided this morning but the 18-day stand-off continued to force Sharif's resignation over alleged rigging during last year's elections.
Cricketer-turned-politician Imran Khan vowed to fight till death and asked Pakistanis to rebel against the "illegal" regime while the other anti-Sharif protest leader cleric Tahir-ul Qadri alleged seven of his supporters were killed by security forces which could not be confirmed.
General Sharif called a meeting of his corps commanders to discuss matters relating to the internal security situation.
The army holds the key to resolving the impasse which has plunged the country into the worst crisis, 15 months after Sharif's PML-N was voted to power.
Among those injured in the overnight clashes were several journalists.
Reporters, who were covering the protests, were brutally tortured by rioters and the police.
Meanwhile, the government on its part, said it was trying to re-open talks with opposition groups.
Information Minister Pervaiz Rashid said the government remained open negotiations to end the crisis peacefully.
"The government did not initiate the clashes. They turned violent and tried to enter sensitive government buildings, which are the symbol of the state," Rashid was quoted by Geo News channel as saying.
"They wanted their demands to be met at gunpoint but still, our doors are open for talks," he said.
Sharif, who yesterday went to Lahore with his staff, returned to the capital today.
Yesterday, Sharif dismissed the protests, describing it as a "tiny storm" that will end soon.
"This is just a tiny storm, a tumult, which would be ended in a few days," Sharif said.
Indicating that certain forces were trying to target him, the Pakistan Premier asserted that "conspiracy" against democracy will not be tolerated.