The Philippine president signed a bill criminalizing all forms of torture and prohibiting state authorities from using secret detention centers, her spokesman announced Friday.

President Gloria Macapagal Arroyo's government, which has been fighting communist and Muslim insurgencies, has come under severe criticism from international rights groups, the U.S. State Department, and a U.N. investigator on extrajudicial killings in the deaths of hundreds of left-wing activists.

Officials said the deaths were not sanctioned by the state. Government and human rights groups differ on how many people have died, with some estimates as high as 1,000.

The announcement came as U.S. Secretary of State Hillary Rodham Clinton was visiting the country.

The New York-based Human Rights Watch had urged Clinton to raise concerns during her visit to Manila on Thursday and Friday over hundreds of people allegedly killed by state forces since Arroyo came to power in 2001, and inadequate efforts to prosecute military personnel believed responsible.

Clinton told a forum in Manila that she raised the human rights issue during her talk with Arroyo and the State Department has pointed out areas it believes could be improved.

"We will continue to raise questions but we will also continue, as a friend does, to offer whatever assistance we can," she said, including training and support to ensure government institutions are protecting human rights.

The law defines torture as any act — physical or psychological — by which severe suffering is inflicted by a person in authority or his agent to get information or a confession.

It provides penalties of up to life imprisonment, depending on the gravity of the offense, and renders evidence obtained through torture as inadmissible in any proceeding.

The law also requires the military and police to submit a monthly report listing all detention centers to the independent Commission on Human Rights.