Jakarta – The US embassy here on Friday deplored the "senseless" and "brutal" murder of three Indonesians involved in the peace process in restless Aceh province, and urged the government to investigate the killings.

"The embassy is particularly concerned that people involved in the search for peace and in promoting human rights are being brutally murdered," an embassy press release said.

"We urge the government of Indonesia to investigate these tragic deaths, and punish those responsible." The three men – a religious leader, a lawyer and a driver – were found with fresh bullet wounds on Thursday, half an hour after they left a district police station in South Aceh.

The Rights group Human Rights Watch said earlier Friday that the murders suggested that Indonesian security forces were deliberately targetting human rights workers in the province.

The religious leader, Teungku Kamal, was a member of a team monitoring implementation of a "peace through dialogue" agreement between separatist rebels and the Indonesian government. He had been called for questioning as a suspect in a defamation case after police said they had been falsely accused of raping five women from the district, Human Rights Watch said.

The lawyer, Suprin Sulaiman, worked for the Coalition for Human Rights NGOs, an organization which received funding from USAID, the embassy said.

The women involved in the rape case, aged 15 to 19, reported the attacks in February to rights groups in the provincial capital of Banda Aceh.

On their return to South Aceh, police took the women into custody. After questioning, they were flown by police helicopter back to Banda Aceh, where they gave a press conference and said their attackers were in fact separatist rebels.

The night before police took the women into custody, they had stayed overnight at a religious school run by Teungku Kamal, Rights Watch said.

Human Rights Watch called for a full investigation by the Indonesian National Human Rights Commission and international experts.

Attacks on rights activists and humanitarian workers in Aceh have increased, the group noted, citing the arrest and torture of three Oxfam workers in August and the kidnapping and fatal stabbing in the same month of New York-based human rights lawyer Jafar Siddiq Hamzah.

The Free Aceh Movement (GAM) has been fighting for a free Islamic state in Aceh since the mid-1970s. More than 300 people have been killed in violence in the province this year. Military repression and siphoning off the province's abundant natural resources by Jakarta have helped fuel the separatist movement.

In Jakarta Wednesday, the Indonesian parliament gave its full support to the government's planned moves to restore law and order through military operations in Aceh.