Opposition leaders arrested in Pakistan
It comes as the Supreme Court was due to rule on the legality of General Musharraf's October election victory.
Meanwhile, troops have been deployed across the capital and the government has blocked private TV channels.
Police surrounded the Supreme Court, ahead of a crucial decision on whether Musharraf could stand in elections while still be head of the army.
The Chief Justice was once again dismissed and a replacement immediately sworn in.
The former Pakistan Prime Minister Benazir Bhutto said she believed the emergency situation was aimed at delaying elections due in January.
She also called on the international community to put pressure on Musharraf to reverse his decision.
Bhutto returned to Pakistan from Dubai on Saturday and left the airport in Karachi with a police escort. Around 100 paramilitaries have surrounded her home.