Jakarta (AsiaNews/Agencies) – Foreign NGOs that wish to continue their post-tsunami aid work in the Indonesian province of Aceh must not "interfere in the internal affairs of the country" by favouring the local pro-independence guerrilla.

The Indonesian government's warning comes amid fears that the influence of NGOs and other aid groups operating in the area after the December 26 tsunami might increase international support for the separatist Free Aceh Movement.

Indonesia's Welfare Ministry, which is in charge of aid coordination, said that aid groups wanting to remain in the province will have to sign 'a memorandum of understanding' (MOU) which they should receive this week. Within 15 days a list of "eligible foreign NGOs should be announced.

Komet Mangiri, an adviser to Welfare Minister, explained that the MOU would contain "the procedures and conditions that must be fulfilled by the Non Governmental Organisations, such as not interfering in domestic affairs and not working for separatist interests".

Sections of Indonesia's political and military elite are concerned that, like in East Timor in 1999, international aid groups and the UN might facilitate the region's secession.

Jakarta had welcomed foreign NGOs in the days immediately following the tsunami, which killed 130,000 people in northern Sumatra alone.

Last month however, the government announced that only those groups involved in "reconstruction" would be able to stay.

Many in Aceh believe that after the disaster international aid is essential for the region's renaissance.

Aceh rebels have been fighting a war of independence since 1976 in which more than 12,000 people were killed.

Humana rights groups have accused the Indonesian army of abuses against the civilian population, including summary executions, abductions and torture.