General Pervez Musharraf, Pakistan's president, has imposed emergency rule in the country.
State-run television reported on Saturday that the country's constitution has been suspended.
Reuters news agency also said that Iftikhar Chaudhry, the supreme court chief justice, has been told his services are no longer required.
Musharraf is to address the nation later on Saturday, a presidential aide said.
The decision to impose emergency on Saturday came after an extraordinary meeting chaired by Musharraf which was attended by senior government and security officials.
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