Eight American tourists were killed and 21 injured when their bus collided with a truck near the southern Egyptian city of Aswan.
The bus was headed to the ancient Egyptian Abu Simbel temples and was carrying 37 tourists when it collided with a damaged truck parked on the side of the road.
A police official said six of the dead were women. The bus driver and a tourist guide were also injured in the crash, which occurred early in the morning about 30 kilometres from Aswan.
Four tourists are in a critical condition at a military hospital in Aswan.
The US embassy said in a statement that it was "deeply saddened by the traffic accident in Aswan that has led to deaths and injuries among American tourists." It did not provide a toll.
It said the injured were being moved by military transport to Cairo. The police official said some of the injured tourists would be airlifted in the afternoon to a hospital in Cairo that often treats injured tourists.
Seventy-nine tourists on board two other buses in the convoy were unharmed, MENA reported.
Traffic accidents occur frequently in Egypt, often because of poor road condition and lax regulations.
The government estimates that there are 8,000 road accidents a year in the country.
The US State Department warns on its website that travelling on Egyptian highways can be dangerous. Embassy officials are prohibited from travelling outside Cairo after dark because of driving hazards.
Eighteen French tourists were injured when their bus overturned on the same two-lane desert road in January.
The 3,000 year-old granite Abu Simbel temples are a popular tourist attraction.
They were relocated to their present location, about 300 kilometres from Aswan, in the 1960s to prevent them from being submerged by rising waters from the Aswan Dam which was under construction.