Pakistan's parliament is holding an emergency session to rally political support for Prime Minister Nawaz Sharif, who is refusing to resign despite weeks of opposition protests.
Addressing the opening meeting, Interior Minister Chaudhry Nisar Ali Khan slammed the protests as a "revolt against Pakistan" being led by "fake revolutionaries" and "terrorists."
For more than two weeks, thousands of protesters led by cricketer-turned-politician Imran Khan and populist cleric Tahir-ul-Qadri have camped out in the central part of Islamabad.
They are demanding the prime minister, who took power last year, resign over alleged election fraud and widespread corruption.
The protests had been mainly peaceful until this weekend, when clashes erupted between protesters and security forces, killing three people and injuring hundreds.
Monday witnessed more pitched battles between protesters and police. Demonstrators briefly took over Pakistan's state television station, forcing the channel off the air.
Khan on Monday vowed not to call off the anti-government protests until the prime minister resigns.
"We are saying to Nawaz Sharif that he should now step down, because today people will come out all over Pakistan against him, and there will be losses to the Pakistani people, and will be losses to people's property, all because of you, and you have no moral ground to continue as prime minister," said Khan.
Khan distanced himself from the attack on the TV station, promising punitive action if anyone from his party found guilty, and reiterated his protest is peaceful.
In Washington, State Department spokeswoman Jen Psaki said the United States supports the right of peaceful protest, but urged the demonstrators and the government to show restraint, and said destruction of property is not an acceptable way to resolve political differences.
Police also have attacked television crews and reporters covering the protests. Police have been seen dragging journalists out of vans and beating them with sticks. Some have been seriously hurt.
In his Tuesday speech, Interior Minister Khan apologized on behalf of his government and promised action will be taken against police officers responsible for the violence against media.