A state of emergency has been declared in the Philippines by President Gloria Macapagal Arroyo after military officials said they blocked a coup attempt against her.

According to foreign news reports, she made the move to assert control during a television address on after Lt Gen. Hermogenes Esperon earlier said, "We believe that we have quashed a coup."

Talk of plots against Arroyo, who survived a crisis last year over allegations of vote-rigging and corruption, has been running high around this week's anniversary of a "people power" revolt that toppled dictator Ferdinand Marcos in 1986.

"I have declared a state of emergency," the president said in a taped address on television and radio, adding she had authorised the military and police "to take ample measures".

"This is my warning to those who are attempting anything against the government."

According to Reuters , executive orders do not require approval by Congress.

Commander detained

Emergency rule, which allows arrests without warrants and an extension of detention without charge, is a very sensitive issue in the Philippines after nine years of martial law under Marcos.

Another report quoted Armed Forces chief General Generoso Senga as saying that the commander of the elite Scout Rangers regiment had been detained.

He was the alleged leader of troops who planned to join protests against Arroyo by her political foes today.

The army said the rogue troops were planning to announce to the protesters that they were withdrawing support from the president, hoping this would spark an uprising against Arroyo.