The soldiers were looking for weapons and other evidence
Security forces in the Philippines have raided the compound of a powerful family in a southern province suspected of involvement in political killings.
One member of the family is currently in police custody, charged with multiple counts of murder related to the mass killing last week.
Among the 57 victims were members of a rival clan and 30 journalists.
Heavy weapons and ammunition were earlier found buried near the Ampatuan family compound in Maguindanao region.
For the past few days troops have surrounded the compound of houses where the Ampatuan family is based.
Early on Friday morning, police investigators backed by soldiers with metal detectors and sniffer dogs moved in looking for weapons.
They first searched the house of the only suspect who has been charged in connection with last weeks killings, Andal Ampatuan Jr.
They then moved on to the house of his father, Andal Ampatuan Sr, and other family members.
Crates of bullets were found at Mr Ampatuan Jr's home. Some reports said the ammunition was for high-calibre machine-guns.
Police allege that Mr Ampatuan Jr led a force of 100 gunmen to ambush and kill members of a convoy that included the family members and supporters of a political rival.
Heavy weapons and ammunition were found outside the Ampatuan compound
He has been charged with 25 counts of murder.
Friday's raid followed the discovery of what a military spokesman described as an arsenal of weapons buried several hundred metres outside the Ampatuan compound in Maguindanao's capital, Shariff Aguak.
"We estimate that these weapons are enough to arm a battalion [500 soldiers]," national police chief Jesus Verzosa said.
He said the weapons had been recently buried and included anti-tank recoilless rifles, mortars, machine-guns, rifles, pistols and ammunition.
The chief of the armed forces has ordered an investigation into how the military weapons ended up in the hands of the Ampatuans.
The government has armed militias in the south to act as an auxiliary force to the army and police battling insurgents but they often end up as the private armies of local strongmen.
Also on Friday, prosecutors issued subpoenas to six members of the Ampatuan family, including the patriarch, Andal Ampatuan Sr, to appear at a hearing on 18 December.
They and other members of the family have been placed on an official watch list aimed at preventing them from fleeing the Philippines.
The Ampatuan clan have long controlled Maguindanao province and have been loyal supporters of President Gloria Arroyo.
Since the killings, Mr Ampatuan Jr, his father and his brother Zalday have been expelled from her party.
She has promised that the gunmen would not escape justice.