A Quezon City court has ordered the arrest of a powerful political clan's patriarch and 195 others on murder charges over the massacre of 57 people last year, police said Thursday. The massacre last November was the worst incident of election violence in the Philippines and has raised security fears over elections on May 10. The order for the arrest of Andal Ampatuan Sr, whose family has ruled the poor and troubled southern Maguindanao province for nearly a decade, came before Friday's official start of local campaigning for Congress positions in the May polls. Ampatuan, three of his sons and a brother will face 57 counts of murder before the Quezon City regional trial court. All five are already in custody on other charges. The Supreme Court moved the case from Mindanao island because of security concerns. A fourth son, Andal “Unsay” Ampatuan Jr, the principal suspect, has already been arraigned for the murders. “We got copies of the arrest warrants today and served them to those who are already in our custody,” said Francisco Montenegro, head of the national police agency's criminal investigation and detection group. Of the 196 charged with the murders, 55 are under military and police custody. Those still at large include soldiers, police officers and members of a civilian militia “We continued to hunt them down and search for weapons that might have been used in the murders of 57 people. We're also gathering more evidence to pin them down for the murders,” Montenegro said. The arrest warrants were issued six weeks after state prosecutors filed the murder charges against Ampatuan and 24 other members of his family, 65 soldiers and police officers, and 106 members of a civilian militia force. Thirty local journalists, 20 civilians and seven members of a rival clan of the Ampatuans were attacked by about 100 armed men while on their way to witness the filing of nomination papers of a candidate preparing to stand in elections. The deaths heightened the Philippines' profile as one of the most dangerous places in the world for journalists, and stoked tensions ahead of the elections. The campaign period for local seats begins Friday. Security forces anticipate more violence in provinces and towns where there is intense political rivalry and a heavy presence of rebels and armed groups. Apart from the Maguindanao massacre, about 40 people have died in poll-related violence since late November. Ampatuan Sr is under heavy guard at an army hospital in Davao City on southern Mindanao island, while his brother and his three sons are detained at a police base in another southern city.