A well-armed and organized group is responsible for recent killings of at least 12 Christians on the island of Sulawesi, Indonesia's national police chief said, though he would not say if it was an organization with links to al-Qaida.
The murders have raised fears of a return to the widespread bloodletting that left more than 1,000 people dead between 1999 and 2001.
Sectarian conflict in the region worsened during that period with the arrival of Laskar Jihad, a Muslim militia believed to be supported by hardline elements in the Indonesian army.
In a speech in the central Sulawesi town of Poso, General Da'i Bachtiar declined to label the murder group and sidestepped questions about reported involvement of Jemaah Islamiyah, the terror group linked to al-Qaida. Investigators have revealed no motive for the attacks.
Bachtiar joined Welfare Minister Jusuf Kalla in encouraging residents to provide information on the killers' network, training camps and members.
A peace agreement signed in December 2001 ended two years of fighting between Christians and Muslims in and around Poso. The agreement had held until the recent attacks.
About 90 percent of Indonesia's more than 210 million people are Muslims, making it the world's most populous Islamic country. The remainder are mostly Christians, Hindus and Buddhists.