Musharraf imposes emergency rule BBC
Pakistan's President Pervez Musharraf has declared emergency rule, state-run TV has said, amid reports that police have surrounded the Supreme Court.
Judges are believed to be inside the building in Islamabad, reports say.
Troops have been deployed inside state-run TV and radio stations, while independent channels have gone off air.
Gen Musharraf is awaiting a Supreme Court ruling on whether he was eligible to run for re-election last month while remaining army chief.
Pakistan has been engulfed in political upheaval in recent months, and the security forces have suffered a series of blows from pro-Taleban militants opposed to Gen Musharraf's support for the US-led "war on terror".
The BBC's Barbara Plett reports from Islamabad that fears have been growing in the government that the Supreme Court ruling could go against Gen Musharraf.
Land and mobile telephone lines are down in Islamabad, reports say.
Private channels Geo News and Dawn News earlier quoted unnamed sources as saying the government had made up its mind to declare emergency rule. Shortly afterwards they came off air.
One TV channel reported that emergency rule may involve the suspension of the constitution.
Parliamentary elections are due in January - it is not clear whether they will go ahead.
Former Prime Minister Benazir Bhutto, who recently returned to the country after years of self-exile to lead her party in the elections, is currently in Dubai on a personal visit.