Philippine prosecutors filed charges of rebellion on Wednesday against five members of a powerful local clan over the massacre of 57 people in the south of the country.

Nineteen others were also charged with rebellion, which carries a sentence of life imprisonment, in connection with the killings. The massacre prompted the authorities to impose martial law in Maguindanao province at the weekend.

Police took the Ampatuan clan members, including the patriarch who is a close ally of President Gloria Macapagal Arroyo, into custody on Saturday.

Prosecutors said that after the killings, those charged had directed each other “to rise publicly and take arms against the Republic of the Philippines”.

“There were massive formations of numerous armed civilians supported by armored vehicles and under the command of the Ampatuans who have formed a private army to resist government troops...,” said the charge sheet, signed by acting Maguindanao provincial prosecutor Leo Dacera.