"Philippine President Gloria Arroyo has declared a state of national emergency, after the army said it had prevented an attempted coup.
She said was taking the action "because of the clear threat to the nation".
A senior general has been arrested for allegedly planning to lead troops taking part in civilian protests.
In recent days, there have been growing rumours of a coup timed to coincide with Saturday's 20th anniversary of the ousting of President Ferdinand Marcos.
The BBC's Sarah Toms in Manila says coup rumours are common in the Philippines, which has seen a dozen attempts to overthrow the government in the past 20 years.
Two of Mrs Arroyo's predecessors, Marcos and Joseph Estrada, were ousted in public revolts."
Article: BBC News