The Philippine president on Friday signed-off on a widely-opposed anti-terror law which critics fear could be used to target human rights activists.

President Rodrigo Duterte signed the controversial Anti-Terrorism Act after it was approved by Congress. Among other things, it allows Duterte to appoint a council that could order warrantless arrests of people it deems as terrorists.

"The signing of the law demonstrates our serious commitment to stamp out terrorism, which has long plagued the country and has caused unimaginable grief and horror to many of our people," Duterte's spokesman Harry Roque said.