Jakarta – Indonesian President Susilo Bambang Yudhoyono will not respond to a letter from 40 members of US Congress demanding the immediate release of two Papuan activists, a spokesman said Tuesday.

The presidency spokesman said the appeal for the release of the two men jailed for raising a separatist Papuan flag was "small stuff" and would be handled by the embassy in Washington.

"The president doesn't need to answer the letter because this is only small stuff. We have too many important things to tackle such as independence day (August 17)," spokesman Dino Patti Djalal said.

"We will ask the foreign ministry to give a response through our ambassador in Washington."

Filep Karma and Yusak Pakage were sentenced to 10 and 15 years respectively in 2005 for raising the separatist Morning Star flag at a protest in the Papuan capital of Jayapura in late 2004. Amnesty International has declared the two "prisoners of conscience."

In the letter addressed to Yudhoyono, the lawmakers called the activists' imprisonment "unjust" and said it came amid a "crackdown on Papuan human rights defenders."

"This campaign of threats and intimidation has targeted Papuans who met with and gave testimony about human rights abuse to a senior UN human rights representative when she visited Papua at your government's invitation in June 2007," it said.

"We urge you to take action to ensure the immediate and unconditional release of Mr. Karma and Mr. Pakage... Such steps would be an important indicator that Indonesia, as a member of the UN Human Rights Council, takes its international obligations to fully respect universally recognized human rights."

The presidency said the letter was based on false information from "anti-government groups" and did not reflect the position of the US government, which recognises Indonesian sovereignty over West Papua.

Hardline Muslims rallied outside the US embassy in Jakarta on Saturday to condemn the letter, holding banners reading: "We are against US intervention in Papua."

Indonesia took control of Papua, a former Dutch colony on the western half of New Guinea island, in 1969 after a vote among a select group of Papuans widely seen as a sham.

Papuans have long accused Indonesia's military of violating human rights in the province and complain that the bulk of earnings from its rich natural resources flow to Jakarta.