At least 40 people were injured by eight boulders that fell from cliffs into a shanty town in Cairo's eastern Duwayqa neighborhood Saturday, the BBC reported.

Rescue teams were forced to wait for heavy construction equipment to arrive to move the massive boulders, some of which weighed more than 70 tons. Officials said it wasn't clear what triggered the rockslide, but local residents blamed it on nearby construction work, the broadcaster said.

"The power went out, we heard a loud bang like an earthquake and I thought this house had collapsed," Hassan Ibrahim Hassan, 80, told the BBC. "I went out, I saw the whole mountain had collapsed. It was horror."