MANILA: Human Rights Watch (HRW) on Thursday urged Philippine President Benigno Aquino to do more to break up private armed groups, after 58 people were killed in the country's worst political massacre three years ago.

The watchdog's Asia director Brad Adams said the government had failed to disband dozens of so-called “private armies” following the Nov 23, 2009 massacre in Maguindanao province that was blamed on a powerful local clan.

“Three years since the horrors of the Maguindanao massacre, the trial crawls along, half of the suspects remain at large, and the victims' families still face threats,” Adams said in a statement.

Aquino’s spokesman Ramon Carandang said police had carried out raids against such groups, leading to some arrests.

He cited an interior department report that showed only around 60 private armed groups remained, compared with 112 at the end of 2010.

Adams said Aquino should revoke an order issued by his predecessor Gloria Arroyo that authorised local officials to form and arm civilian paramilitary units to help law enforcers keep the peace in areas troubled by insurgencies.

HRW said the order had been abused by many local officials in justifying their own “private armies” that he said they then used against political rivals.

The Ampatuan clan is accused of carrying out the 2009 massacre in their Maguindanao provincial stronghold to stop a rival, Esmael Mangudadatu, from running against one of its members in elections the following year.

The victims included Mangudadatu's wife and sister, their lawyers and a large group of journalists.

Philippine police said 103 people have been arrested over the massacre, including the clan patriarch. However 92 other suspects remain at large.