Marianne Kearney, Darussalam – Dozens of Muslim and Christian groups are exploiting the chaos wrought by the tsunami in the Indonesian province of Aceh to spread their message and compete for influence, secular aid workers said yesterday.

Many religious charities are offering purely humanitarian aid and have policies against proselytising but some have made blatant attempts to win hearts and minds.

An American missionary organisation has claimed to have flown out large numbers of orphans to be looked after and educated in Jakarta, the capital of Indonesia. More than 110,000 people have died in Indonesia and hundreds of thousands are without adequate food, shelter and medicine.

The Virginia-based group WorldHelp said on its website in an appeal for funds that it had airlifted 300 "tsunami orphans" to Jakarta, to be raised in a Christian centre. "If we can place them in a Christian children's home, their faith in Christ could become the foothold to reach the Aceh people," it said.

The appeal said WorldHelp was working with Indonesian-born Christians who want to "plant Christian principles as early as possible", reported The Washington Post.

After WorldHelp was contacted by the newspaper, it removed the appeal.

Aid workers in Aceh said they had not heard of the organisation or the removal of large numbers of children.

At a relief camp in the grounds of the mosque in Darussalam, five miles outside Banda Aceh, the provincial capital, a volunteer from a conservative Muslim boarding school claimed that an Islamic political party had removed 20 orphans to Jakarta.

That claim could not be substantiated but amid the confusion at the camp the competition between rival groups was clear. Late in the afternoon Ahmad Salikun, the volunteer, gave children a lesson on the Koran.

Downstairs four foreigners in Church of Scientology T-shirts, said to be Americans, were offering massage to refugees lounging on rattan mats. The church has set up an office in Banda Aceh.

The Scientologists are unlikely to make many inroads among the devoutly Muslim population, but they could easily provoke clashes and a subsequent crackdown on humanitarian groups, international aid organisations fear. "You take traumatised people and do counselling for them, this is very dangerous," said one aid worker who has been in Aceh for years.

Christine Knudsen, a child protection officer with Save the Children, said the radical Islamic groups that have moved in from Java were at odds with Acehnese tradition. Devout but tolerant, the Acehnese Muslims have turned away hardliners in the past.

But with their society devastated by the tsunami, and the militant groups receiving the implicit backing of the Indonesian military, observers fear that the Acehnese will be unable to resist attempts to impose more hardline Muslim values.