Pakistan President Pervez Musharraf has decided to impose emergency rule, state-run television said on Saturday, in a move expected to put off elections due in January.

The government blocked transmissions of private news channels in several cities and telephone services in the capital, Islamabad, were cut.

"The chief of army staff has proclaimed a state of emergency and issued a provisional constitutional order," a newscaster on Pakistan TV said, adding that he would address the nation later Saturday.

Nuclear-armed Pakistan's internal security has deteriorated sharply in the past few months with a wave of suicide attacks by al Qaeda-inspired militants, including one last month that killed 139 people.

Pakistani paramilitary troops and police surrounded the Supreme Court in Islamabad after the declaration of emergency. Two trucks full of armed paramilitary soldiers from the Rangers force, who are under the control of the Interior Ministry, and several dozen policemen cordoned off the building.

Musharraf, who seized power in a 1999 coup, is awaiting a Supreme Court ruling on whether he was eligible to run for re-election last month while still army chief.

Stung by criticism it was adding to a sense of instability, the court said on Friday it would reconvene on Monday and try to finish the case quickly, having earlier said it would take a break until Nov. 12 -- just three days before Musharraf's current term is due to expire.

Witnesses also said paramilitary troops were deployed at state-run Pakistan Television and radio stations ahead of the announcement, which follows weeks of speculation that US ally Musharraf might impose emergency rule or martial law.

About 139 people were killed on Oct 19 by an attempted suicide bomb assassination of opposition leader Benazir Bhutto during a procession through Karachi when she returned from eight years of self-imposed exile.

Meanwhile, a report said Bhutto will not return to Pakistan from Dubai following the declaration of emergency. She went to Dubai on Thursday.

Speaking about the emergency, hHer husband, Asif Ali Zardari, said: 'It's definitely not pleasant news, it's not welcome news...We're hoping to build institutions, not destroy them.'  
 
Before the announcement on emergency rule, US Secretary of State Condoleezza Rice had told journalists travelling with her to Turkey that Washington opposed any authoritarian measures and wanted elections to go ahead.

'I think it would be quite obvious that the United States would not be supportive of extra-constitutional means,' Rice said. 'Pakistan needs to prepare for and hold free and fair elections.'    

Musharraf had said he would quit as army chief if he was  given a second term, and he had allowed Bhutto back into Pakistan to lead her party into the national elections.