Egypt has apologised after 12 people, including eight Mexican tourists, were mistakenly killed by security forces in an anti-terror operation.
The group had permission to travel to a remote area of the Western Desert, tourism officials said.
However, the interior ministry insists they entered a restricted area.
Egypt has been battling Islamist militants for years, with attacks escalating since the 2013 ousting of Islamist President Mohammed Morsi.
While the vast Western Desert is a popular tourist site, it has become increasingly dangerous because of the deteriorating security situation in Libya.
Ten Mexicans and Egyptians were injured in the operation. Security officials put the number of Mexican tourists killed at eight, although this is yet to be confirmed by Mexico, with four Egyptians dead.
Egyptian Prime Minister Ibrahim Mahlab offered his apologies in a phone call to the Mexican ambassador in Cairo, the Al-Yawm al-Sabi website reported.
“I have phoned Mexican Ambassador Alvarez Fuentes to reassure him that the injured are receiving proper medical care and that the government apologises for the foreign casualties,” the website quoted him as saying.