The massacre has cast a shadow over the 2010 elections
The Philippines has charged 196 more people with murder over a pre-election massacre in Maguindanao province in November which left 57 dead.
Those charged include Andal Ampatuan Snr, formerly a provincial governor and ally of President Gloria Arroyo.
Mr Ampatuan's son of the same name has already been charged with murder over the attack on a rival political family and journalists travelling with them.
The charges come as campaigning opened for the presidential elections.
Prosecutor Leo Dacera of the Department of Justice said those charged had been positively identified as "direct participants in the commission of the crime of murder", the AFP news agency reported.
The agency quoted justice department papers as saying that all the accused were "answerable as co-principals regardless of the extent or degree of their participation".
It was unclear how many of the accused were already in police custody, but all are expected to seek bail.
Lawyers representing the journalists killed told the BBC the case would now become a logistical nightmare, as bail hearings would delay the start of the trial.
The victims were part of a group on their way to file the candidacy of one of their leaders, Ismael Mangudadatu, for the May elections.
Several women were among the group, including Mr Mangudadatu's wife and pregnant sister.
They were ambushed and shot by around 100 armed men - their bodies were found in a mass grave in a secluded mountainous area of the province.
Mr Ampatuan Snr is the head of the powerful Ampatuan clan that controlled local politics in Maguindanao and ran a private army.
He has served in the Philippines Congress and won the governorship of Maguindanao unopposed for several terms.
His son, Andal Ampatuan Jr, was reportedly planning a similarly unopposed run to replace his father, but then Mr Mangudadatu decided to run as well.
He denies the charges and is currently awaiting a bail hearing.
The BBC's South East Asia correspondent Alastair Leithead says all those in custody are also expected to lodge bail applications - all of which have to be heard before the trial can begin.
Lawyer Harry Roque, who represents families of the journalists killed, said that as Mr Ampatuan Jr's bail hearing had already taken so long, he was concerned that so many people had been added to the charge.
"The fact that the system is moving does not necessarily mean that the system is, in fact, healthy," he told the BBC.
"What we need right now are convictions, because the obligation of the state is not just to indict but to successfully prosecute the perpetrators of this act."
Officials said the next step was for all the accused to be transferred from the southern Philippines to Manila for the court proceedings.