MANILA, Philippines (AP) — An international human rights watchdog said Wednesday it has information that sympathetic Philippine military personnel were thwarting attempts by civilian authorities to capture a former army general accused of kidnapping two student activists.

Retired Maj. Gen. Jovito Palparan has been on the run since he was charged in December with kidnapping two left-wing activists in 2006. The students remain missing.

Palparan, a former congressman who was close to former President Gloria Macapagal Arroyo, has denied any involvement. He is the highest-ranking military official to face allegations of abuse that human rights groups say has long been tolerated in the Philippines.

Rights groups and a U.N. investigator have blamed security forces for the deaths and disappearances of about 1,000 activists between 2001 and 2010, when Arroyo was president.

Human Rights Watch said civilian officials told the group that Palparan is being protected by some military personnel and business owners who benefited from his heavy-headed tactics to suppress a long-running communist insurgency.

“There are concerns that the military may be interfering in the civilian judicial process,” the New York-based watchdog said in a statement.

Military officials have denied allegations of sheltering Palparan and two soldiers accused with him, and they have promised to cooperate in the investigation against them. In December, however, a group of active and retired military officials publicly defended Palparan and warned that his prosecution was causing “demoralization in the soldiers’ ranks.”

The other soldiers charged, Lt. Col. Felipe Antado and Staff Sgt. Edgardo Osorio, have surrendered. A court has allowed them to be transferred from civilian to military custody despite protestation from Justice Secretary Leila de Lima, who said the army failed to inform her where the two are being held, or if they are confined at all.

The conservative military has often acted as an influential power broker, and its members have launched several coup attempts since 1986.

The deputy Asia director for Human Rights Watch, Elaine Pearson, called on President Benigno Aquino III to put officers and soldiers on notice “that if they block civilian authorities in arresting Palparan, they too face legal consequences.”

“President Aquino should get the message to the military that the years of protecting Palparan for grievous abuses are over,” she said.

Aquino’s government has said it wants justice for the missing students, Karen Empeno and Sherlyn Cadapan, as part of a push to improve the Philippines’ human rights record after a decade of rampant abuses during Arroyo’s administration. Arroyo gave the military a free hand in what it had called an all-out war against communist rebels.

About 5,000 rural-based communist guerrillas known as the New People’s Army continue to attack military and police outposts, extort money and raid business establishments it accuses of exploiting workers. It is listed by U.S. and European governments as a terrorist organization, but has been engaged in peace talks with the Philippine government.