At least 15 people drowned Wednesday night when a ferry collided with a cargo boat and capsized on the Nile River north of Cairo.
Egyptian police arrested the captain of the cargo boat and his deputy after the crash. Emergency workers rescued six people.
The health ministry said efforts to locate those unaccounted for were continuing early Thursday. Darkness was hampering the search.
Traffic has been heavy along the Nile as Egyptians celebrate the end of the holy month of Ramadan.