MANILA, Philippines?Senator Rodolfo Biazon will ask next week for a Senate investigation into who was responsible for giving a large number of arms and ammunition to the Ampatuans as these could have been procured only by the military and the police.

Biazon, who chairs the Senate national defense committee, said he was "aghast'' at the military?s uncovering of an arms cache buried near the house of Andal Ampatuan Jr., especially the three recoilless rifles which he stressed were primarily intended to be used against tanks.

"Only the military can have this weapon,'' he insisted in a phone interview. "Nobody can possess them, except for the military and the police, once in a while.''

Biazon said he will file a resolution next week in the Senate calling for the investigation, saying he was doing this out of concern for the plight of soldiers, many of whom have complained about the shortage of arms and ammunition in the battlefield.

"I would like to investigate who gave these arms,'' he said, adding he was assuming the arms found buried on a vacant lot barely a kilometer from the homes of the Ampatuans in Shariff Aguak belonged to them.

The government is currently investigating the death of 57 persons who were slaughtered in Maguindanao, including members of the Mangudadatu clan, rivals of the Ampatuans for government power in Maguindanao.

Biazon, a former Armed Forces chief of staff under the Corazon Aquino administration, said these arms were "restrictive items,'' which was why an explanation from the military was necessary.

It's possible "some higher-ups'' were involved, according to Biazon.

Meanwhile, Senator Antonio Trillanes IV said Friday the discovery arms cache confirmed "our claim that, during all this time, the arms and ammunition of warlords and other rogue groups which have wreaked havoc in our country are being supplied and sourced from the arsenals and factories of the Armed Forces of the Philippines and the Department of National Defense.''

"This corrupt and condemnable practice has not only led to the sacrifice of countless lives of soldiers, law enforcement officials and innocent civilians but has been fueling the endless war in Mindanao and other volatile areas. This was also one of the root causes which impelled us to demonstrate and speak out against the current administration at Oakwood way back in 2003; at Manila Pen two years ago; and whenever we get the chance to be heard,'' Trillanes said in a statement.

He was referring to his involvement in the mutiny of soldiers who occupied the Oakwood hotel in Makati City in 2003 and the occupation of Peninsula Manila hotel, also in Makati, in 2007.

Trillanes said President Gloria Macapagal-Arroyo and former Defense Secretary Gilbert Teodoro, should "be made accountable for all the deaths caused by these guns.''