The petitioners and human rights groups have accused police and military officials of abducting and detaining the activists, including two consultants for communist rebels who were negotiating with the government before the guerrillas suspended talks two years ago.
The activists disappeared between May and June, their families said. The national police chief and the head of the Armed Forces, among other top officials, were named as respondents in the petition.
Officials did not comment immediately, but earlier this week the military denied it was holding two student activists after the court ordered Army officials to explain the students’ whereabouts.
Another hearing was scheduled for Monday.
The abductions were part of a government plan to stifle dissent and strengthen President Arroyo’s hold on power, the petition said.
"Only this most honorable court can stop this illegal practice, which has never been heard and experienced since martial law during the dictatorship of (Ferdinand) Marcos," it said. Marcos’ iron-fisted rule ended in 1986 after the EDSA I people power revolt.
The local human rights group Karapatan said the number of missing civilians was on the rise, with 179 alleged state-sponsored abductions since 2001 - 38 of them involving left-wing activists.
In the same period, 717 civilians, including 305 left-wing activists, have been killed by suspected security forces, who often refer to left-wing groups as fronts for communist rebels.
Philippine National Police (PNP) chief Director General Oscar Calderon said yesterday police were investigating all possible suspects, including people in uniform.
Mrs. Arroyo on Tuesday gave the Department of Justice and the PNP a 10-week deadline to make arrests.
The missing activists were identified as Prudencio Calubid, Rogelio Calubad and his son Gabriel, Philip Limjoco, Leopoldo Ancheta, Rolando Porter, Celina Palma, Gloria Soco and Ariel Beloy. — AP, Jose Rodel Clapano