Thailand has limited the use of shackles on more than 500 prisoners who committed serious crimes in a move to conform to international human rights standards.

Prime Minister Yingluck Shinawatra said Wednesday the initiative also shows the government's intent to switch its emphasis from punishment to rehabilitation of inmates.

Under the pilot project, 563 well-behaved inmates out of 800 prisoners at Central Bangkwang Prison have had the shackles removed from their ankles since January.

Previously, prisoners who committed serious offenses were required to wear shackles in jail for security reasons.

Independent committees and rights activists have urged the government to ban the practice to follow international norms.

The inmates still have to wear handcuffs and leg shackles when appearing in court.