Eighteen people were killed after two buses sank into a canal in west Luxor in the early hours of Tuesday.
The accident left 13 injured, four of whom had already left hospital, said Luxor Governorate Spokesman Badawi al-Masry. The majority of the victims were women and children, Masry added.
The microbuses were transporting passengers back from a wedding, Masry said. He blamed the accident on the microbus drivers' "recklessness".
The governor of Luxor, Tarek Saad al-Deen ordered the formation of a committee to look into the cause of the accident. The governor visited the injured in hospital.
On Friday, two tourist buses collided in a Sinai road, leaving 44 people killed.
According to a report released by the Central Agency for Public Mobilisation and Statistics (CAPMAS) in June, the number of car accidents occurring in Egypt in 2013 rose by 0.4 percent when compared to the 2012 figure.
