Washington also urged more than 100,000 Americans living in the former US colony to "take prudent steps to ensure their personal safety during this uncertain time," US embassy spokesman Matthew Lussenhop said in a statement read on national television.

Arroyo on Friday declared a "state of national emergency", invoking powers to use the military to quell a rebellion and to take over public utilities if necessary, after the government detained several people including a general who it said withdrew his support for Arroyo, the commander-in-chief.

"We call on the Government of the Philippines and the Filipino people to respect fully the rule of law, protect civil liberties and human rights, and reject violence," the US statement added.