The 2,000-strong private army of a powerful clan suspected of carrying out the Philippines' worst political massacre was better armed than the military and police, leaked US embassy cables showed.
The cables from late 2009, released by anti-secrecy website WikiLeaks, described the reach of the feared Ampatuan clan in the southern region of Mindanao and said it had authorities on the run.
Key members of the clan and its private army are now being tried for the murder of 57 people in Mindanao in 2009 but many of the accused are still at large, making witnesses reluctant to come forward.
"We estimate that the Ampatuan clan maintains a private army of up to 2,000 men -- who are often better armed and equipped than their (police) and (military) counterparts," an embassy cable said.
"Government officials were astonished by the size of the arms caches and the power of the weaponry" that was later recovered from the Ampatuans, another cable said.
However, the files also said the government had turned a "blind eye" to such private armies because they helped in the fight against Muslim insurgents.
"They are often politically allied with the President," one cable added, referring to then-president Gloria Arroyo.
The Ampatuans were allies of Arroyo but she disowned them after they were linked to the murder of 57 political rivals, lawyers and journalists in a bid to prevent a rival from challenging them in elections in 2010.
The embassy also noted that Arroyo had to impose martial law in the affected area in order to arrest the suspects, disarm the Ampatuans and restore order.
"There are many areas in the Philippines... where armed groups have proliferated and the national authorities have a very limited capability to impose order," the secret documents warned.
Although many key members of the Ampatuan clan have been arrested, victims' relatives have expressed concern that, in the Philippines' notoriously overburdened justice system, the trial could take years to complete.