Egypt's interior ministry said Wednesday that a sonic boom from an overflying aircraft was the cause of a loud "blast" that sent the capital's residents in a panic. "The sound of the explosion in the (southern quarter) of Maadi and in central Cairo was the sound of a plane that broke the sound barrier," deputy interior minister Murad Mohsen said in a statement, cited by AFP.
A source close to the Egyptian army said the plane participated in a joint drill with the Saudi air force.
The sound of the blast shook windows in Maadi and was heard as far away as northern Cairo. Earlier, Mohsen said authorities had received reports of an explosion and would be investigating.