MANILA, Philippines?The Philippine National Police is pushing for an independent inquiry into the Maguindanao mass murder to pave the way for an unhampered investigation and to find out the root causes of the gruesome killings, Director General Jesus Verzosa said on Friday.

Verzosa said a fact-finding committee should be formed to be composed of members of the private sector.

?A fact-finding committee should be held so that we will not be seeing only the massacre incident itself, but the underlying reasons why it could have happened. This is one of the important things we should look at. Because if we want to prevent another thing happening in the future, we have to see the root causes of all these things,? Verzosa told reporters at Camp Crame.

He added that the PNP is conducting an internal investigation as to why some of the arms unearthed near the home of Andal Ampatuan Sr. had the markings of Department of National Defense and Camp Crame, the national police headquarters.

?We are conducting an overall investigation and actually we have put into custody a lot of police officers. We are also investigating the mention of different names of the Armed Forces. We have also put into custody several CVOs that are mentioned and we have now charged two CVOs [civilian volunteer organizations],? Verzosa added.

He said that included in the investigation are ranking police officials in the Autonomous Region of Muslim Mindanao.

Apart from this, authorities are also in the process of checking the police uniforms recovered near Ampatuan?s home in Shariff Aguak, Maguindanao.

Police will also be checking if the arms recovered near the Ampatuan home could have been used in the massacre of at least 57 people last November 23.

Police have so far accounted for the rifles used in the crime that belonged to militiaman Ismail Canapia. Canapia is under the custody of police in Manila.