Philippine police say they plan more arrests after President Gloria Arroyo invoked emergency powers to foil an alleged coup plot. Critics say Mrs. Arroyo is using tactics similar to those imposed by former dictator Ferdinand Marcos.

Police spokesman Samuel Pagdilao said Sunday orders for arrests have been issued, as authorities try to round up all those suspected in the alleged coup plot. However, he did not identify suspects or say when detentions would take place.

"There are persons that are still to be accounted for who were responsible for their participation in the failed coup that happened last Friday," he said.

On Sunday local media reports said a retired police general, Ramon Montano, who was arrested Saturday is still being held along with a leftist member of Congress, Crispin Beltran.

Mrs. Arroyo declared a state of emergency Friday, after some military officers were detained for their involvement in the alleged coup.

The president said the move was necessary because the political opposition, along with elements from the extreme left and right, were trying to bring down her legitimately elected government.

But Mrs. Arroyo is coming under fire for her conduct, with the opposition preparing to challenge the legality of her emergency powers in the Supreme Court.