Senior lawyer Zafarullah Khan submitted a petition to the Supreme Court on Tuesday saying the people of Pakistan were "stunned" by the measures governing television, radio and the Internet.

"The Supreme Court has received a petition from Mr Zafarullah Khan," a court official told AFP on condition of anonymity. "It will be decided whether to take it up or send it back in due course."

Musharraf granted the Pakistan Electronic Media Regulatory Authority (PEMRA) extra powers on Monday after criticising coverage of the suspension of chief justice Iftikhar Muhammad Chaudhry on March 9.

The regulator can now seal the premises or confiscate the equipment of television and radio channels, and suspend the licences of offenders. The decree also sharply increases the fine for violation of rules.

The rules came into force as three private television stations said the government had blocked their transmissions.

Police have also registered cases against about 200 journalists for holding a protest against Musharraf's decree in Islamabad on Monday in defiance of a ban on rallies of more than five people.

Chaudhry has become the rallying point for a series of protests against Musharraf's military rule as opposition parties join forces with lawyers and rights groups.

They turned violent in Karachi on May 12 with the deaths of more than 40 people in clashes between pro- and anti-government supporters.

One of Chaudhry's lawyers, retired judge Rasheed Razvi, was in Hong Kong on Wednesday where he urged the United States and Britain to put pressure on Musharraf to ensure free and fair polls.