(CNN) -- Al Qaeda-linked militants have banned three international aid groups from working in Somalia, claiming they are "actively propagating Christianity" in the predominantly Muslim nation.
Al-Shabaab, the Islamist militant group battling Somalia's U.N.-backed transitional government, ordered World Vision, Adventist Development and Relief Agency and Diakonia to cease their operations.
"Acting as missionaries under the guise of humanitarian work, the organizations have been spreading their corrupted ideologies in order to taint the pure creed of the Muslims in Somalia," the militant group said in a statement Monday.
"Along with their missionary work, the proliferation of corruption and indecency has become prevalent as a result of their presence," the statement said, warning other non-governmental groups against engaging in "similar activities".
All three organizations are Christian aid groups. However, as signatories of the International Red Cross and Red Crescent Movement code of conduct, they have specific polices against proselytizing when distributing aid.
World Vision -- which serves about 100 million people in nearly 100 countries around the world -- said it was "surprised and disappointed" by Al-Shabaab's order. The group said it is motivated by its faith to help those living in poverty, but is impartial when handing out aid. CNN