Inside the Cairo massacre in 6 unbelievable scenes (PHOTOS)

Egyptian photographer Mosa’ab Elshamy spent hours at the Rabaa al-Adaweya sit-in while it was surrounded by security forces.

A supporter of ousted President Mohamed Morsi gestures as smoke billows behind him during clashes between pro-Morsi demonstrators and security forces outside Cairo’s Rabaa al-Adaweya mosque on August 14, 2013.

Mosa'ab Elshamy

CAIRO, Egypt — At least 278 people are dead and scores more injured in Egypt's bloodiest day since the uprising two years ago.

Police forces stormed a thousands-strong sit-in of supporters of the ousted President Mohamed Morsi, using live ammunition, armored bulldozers and tear gas to disperse the crowd.

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Egyptian photographer Mosa'ab Elshamy documented the violence.