Christians in southern Egypt say a campaign of fear and intimidation by radical Islamists prevented them from voting on an Islamist-drafted constitution.

A week before the vote, some 50,000 Islamists marched through the city of Assiut chanting that Egypt will be "Islamic, Islamic despite the Christians."

Men on horses rode around wielding swords in Christian districts of the city, evoking images of Muslims conquering Christians in the 7th century.

Residents say Christians who tried to vote in some villages were pelted by stones, forcing them to turn back without casting ballots.

Christians fear that could be a harbinger of their status under a constitution that enshrines a greater role for Islamic law.