President Benigno Aquino signed the law imposing up to life imprisonment for state agents convicted of being involved in enforced disappearances. It's the first major human rights legislation under his nearly three-year-old government.

Presidential spokesman Edwin Lacierda says Mr Aquino signed the law late Friday, two months after it was passed by Congress.

The human rights group Karapatan says more than 1,000 political activists and suspected supporters have disappeared since the 1972-1986 Ferdinand Marcos dictatorship, including more than 200 under Mr Aquino's predecessor, Gloria Macapagal Arroyo.

US-based Human Rights Watch says the new law is the first to criminalise enforced disappearances in Asia.