The tour company said the accident happened around dawn when it was still dark outside.
Six American women and two American men were killed.
Egyptian security officials said the hurt Americans were first transferred to a military hospital for treatment and then 10 of the injured, including two Egyptians, were airlifted to a hospital in Cairo.
Last month, eight foreign tourists were killed in Egypt when their tour bus lost control and flipped over several times.
The Associated Press contributed to this report.