GENEVA — Just a few hundred yards separate two villages at the northern end of Rakhine State in Myanmar, but after a brutal crackdown by security forces in August, a deep chasm of fear now divides the Muslim residents of one from the non-Muslims in the other.

The villagers share the same health clinic, farm adjoining fields and know all their neighbors, but since August residents of the two villages have not spoken to one another.

Dominik Stillhart, operations chief of the International Committee of the Red Cross, said that last weekend the health clinic’s watchman told him: “‘We are very scared. We know that our neighbors there are very scared, too.’”

Three months after Myanmar’s security forces swept through the area, burning down villages in a campaign the United Nations has called ethnic cleansing, and possibly genocide, the residents who remain have become paralyzed by fear, Mr. Stillhart said. His account provided a rare snapshot of conditions in an area still shut off from most international relief agencies and reporters.

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