Jakarta  - Indonesia rejected a demand by a group of US congressmen for the "immediate and unconditional" release of two Papuans convicted for raising a separatist flag four years ago, a presidential spokesman said Tuesday.

Dino Patti Djalal said the foreign ministry will respond through its embassy in the United States.

"The president will not reply to the letter sent by US Congress members but the Foreign Affairs Ministry will do so through the Indonesian ambassador in Washington," Djalal told reporters.

Djalal said the congressmen lacked balanced information about the country and had been influenced by anti-Indonesia groups.

He stressed that no country in the world supported the separatist movement in Papua, while all United Nations members recognize the Indonesia's sovereignty.

A group of 40 US lawmakers sent a letter to President Susilo Bambang Yudhoyono calling for the "immediate and unconditional release" of Filep Karma and Yusak Pakage, and warning that the human rights situation was deteriorating.

The two activists were sentenced to 10 and 15 years respectively for raising a separatist flag in early December 2004.

Yudhoyono pledged to end the conflict in resource-rich Papua and speed up development under an autonomy deal, although critics say it has not been implemented.

Djalal said the foreign ministry will explain the Papua situation and the criminal cases to the congressmen.

"Hoisting a separatist flag in our land is against the laws and will be processed judicially," he said. "They (the US lawmakers) ought to respect our right to uphold our own law."

Papua, the predominantly Melanesian province 3,700 kilometres north-east of Jakarta, is a former Dutch colony that became part of Indonesia in 1964.

Independence activists in Papua have waged a campaign for nearly 40 years to break away from Indonesia, while a low-level armed rebellion has also simmered.

On Saturday, one man was killed after police fired to disperse a crown when a separatist flag was raised in the Papua town of Wamena. (dpa)