At least 15 people, including two children, have been killed on the Nile on July 22 when a cargo vessel hit their chartered boat, medical and security sources said.
Five of the party were rescued from the river but at least six were still missing on July 23.
The interior ministry said the bodies of four babies had been recovered. Several passengers are still missing.
The captain of the cargo boat has been arrested, police say.
It is not clear if the couple thought to be celebrating their engagement were among the dead.
Traffic had been heavy along the Nile, where many Egyptians had been celebrating the end of the holy month of Ramadan.