"The power went out, we heard a loud bang like an earthquake and I thought this house had collapsed. I went out, I saw the whole mountain had collapsed," said Hassan Ibrahim Hassan, 80, whose house escaped the destruction.
"It was horror," he said.
Witnesses described seeing hundreds of distraught people gathered around the site of the destruction, saying they had relatives and friends trapped under the rubble.
Some were scrabbling at the rocks with their bare hands.
Rescue teams were forced to wait for the arrival of cranes and heavy lifting equipment to allow them to move the huge rocks, but as night fell the help had not arrived.
A BBC correspondent says there have been previous landslides in the area.
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