Pakistan's sacked chief justice has called for the people to "rise up" and restore the constitution.
In a telephone address to lawyers in Islamabad, Iftikhar Chaudhry criticised President Pervez Musharraf, who imposed a state of emergency on Saturday.
He said the constitution had been "ripped to shreds" by Gen Musharraf and added it was now "time for sacrifices".
US President George W Bush has led calls for Gen Musharraf to end the emergency and restore civilian rule.
The government crackdown against pro-democracy activists continued on Tuesday with reports of dozens more arrests.
Former Prime Minister Benazir Bhutto, meanwhile, has flown to Islamabad from Karachi.
She says she has no plans to meet President Musharraf and is in the capital to discuss the crisis with other opposition parties.
Ms Bhutto, who has been negotiating a power-sharing deal with the president, has urged him to hold elections on time and step down as army chief.
There have been clashes between police and lawyers in Peshawar, and in parts of the Punjab, with several lawyers seriously injured in the city of Gujranwala.
There were reports of further arrests in the cities of Lahore, Quetta and Multan.
But protests did not appear to be on the same scale as those suppressed by the security forces on Monday.
The president, who is also head of the army, has said he declared the state of emergency because of a crisis caused by militant violence and an unruly judiciary.
Mr Chaudhry was sacked and replaced after he and eight other judges refused to endorse the order, declaring it unconstitutional.
Critics have said Gen Musharraf acted to pre-empt a judgment by the Supreme Court on whether his re-election last month was legal.
Mr Chaudhry told around 500 lawyers on Tuesday: "The constitution has been ripped to shreds. The lawyers should convey my message to the people to rise up and restore the constitution.
"This is a time for sacrifices. I am under arrest now, but soon I will also join you in your struggle."
Mr Chaudhry is under house arrest but his comments were broadcast on the internet by a private television channel.
As he made the address, mobile phone services in most of central Islamabad went down, prompting suspicions they had been cut.
Constitutional safeguards on life and liberty curtailed
Police get wide powers of arrest
Suspects can be denied access to lawyers
Freedom of movement restricted
Private TV stations taken off air
New rules curtail media coverage of suicide bombings or militant activity
Chief justice replaced, others made to swear oath of loyalty
Supreme Court banned from rescinding emergency order
The lawyers chanted slogans such as "There will be war till the constitution is restored" and "Chaudhry we are ready to die for you".
Mr Chaudhry, who defied attempts by the president to oust him in March and was later reinstated by the Supreme Court, has become a symbol of resistance to Gen Musharraf's rule, say analysts.
In a news conference in Islamabad, Ms Bhutto echoed his calls for the constitution to be restored.
"There will be no talks with Musharraf in the given circumstances," she said.
She said her party was ready to form a joint front against tyranny with all political parties and would boycott Wednesday's session of parliament.
Parliamentary elections are supposed to take place by January.
On Monday, Prime Minister Shaukat Aziz said the vote would go ahead on schedule, but his deputy information minister later told the BBC the elections could be delayed by as much as a year.
Lawyers have called for three days of protests and strikes against the suspension of the constitution.
They have boycotted courts and refused to appear before the new judges.
Hundreds of lawyers and political opponents have been detained.
Pakistan has come under heavy international pressure since Gen Musharraf imposed emergency rule.
Mr Bush urged Gen Musharraf to quit his post as head of the army and hold elections as soon as possible.
UN Secretary General Ban Ki-moon called for the release of all those detained since the state of emergency was declared.
The UK has also reiterated demands for a return to civilian rule in Pakistan.
The Netherlands became the first country to suspend aid, and the EU said its members were considering "possible further steps".
But Gen Musharraf said confidence in his government would soon return and insisted he still planned to give up his military post, as he had been scheduled to do this month.