A blast in Cairo's central historic area killed four people this evening, including a French and a US citizen.
Ahmed Adel, a senior official at the Egyptian health ministry said the explosion in the popular tourist area wounded 18 others.
Police sources earlier said the explosion was caused by a man throwing a bomb from a motorcycle.
The bomb went off on one of Cairo 's streets lined with shops catering for tourists. Police sealed off the road which was covered with shattered glass and shops were closed.
There was no immediate indication of motive and no claim of responsiblity as yet.
The bombing was the latest in a series of attacks on tourists in Egypt. Among the wounded are four French people, three Americans, an Italian, a Turk and nine Egyptians.