An American aid group has been expelled from the Darfur region of Sudan, after officials discovered 3,400 Arabic language Bibles in its office.

Texas-based charity Thirst No More says on its website that its main work in predominantly Muslim North Darfur involves repairing and drilling water wells. The website makes no mention of evangelical work.

Officials in Sudan told the state news agency, Suna, that they had decided to expel Thirst No More "for its violation to the Voluntary Work Act, the Country Agreement and the regulations on registration of organisations in Sudan".

According to Sudanese regulations, aid groups are required to give details of their activities to the Sudanese Humanitarian Aid Commission (HAC), and may not start new projects without state approval.

Osman Hussein Abdalla, HAC commissioner for North Darfur, told Suma that Thirst No More had “failed to provide justification” for owning so many Bibles.

Most aid groups in Darfur, including religiously based ones, choose to sign up to the Red Cross code of conduct, which says that aid should not be used to “further a particular political or religious standpoint”.

The country director of Thirst No More, Charlie Michalik, told Reuters in Khartoum that officials were investigating the group’s work, but he did not offer any more details.