Afghanistan's Islamic council has told President Hamid Karzai to stop foreign aid groups from converting locals to Christianity and also demanded the reintroduction of public executions.
The council, an influential group but without binding authority, is made up of Islamic clergy and ulema (scholars) from various parts of Afghanistan and made the warning in a statement during a meeting with Karzai on Friday.
The ulema have always played a crucial role in Muslim Afghanistan and have been behind a series of revolts against past governments.
But since the ousting of Taliban's radical Islamic administration by US-led troops in 2001, Afghanistan has seen an unprecedented period of freedoms.
"The council is concerned about the activities of some ... missionary and atheistic organs and considers such acts against Islamic sharia (law), the constitution, and political stability," said the statement.
"If not prevented, God forbid, catastrophe will emerge, which will not only destabilise the country, but the region and the world."
Quoting what he said were reliable sources, Ahmad Ali Jebrayeli, a member of the council and also a member of parliament, said unnamed Christian missionaries had offices in Kabul and in the provinces to convert Afghans.
"Some NGOs are encouraging them (to convert), give them books (Bibles) and promise to send them abroad," he said today.