Four-wheel drive cars are shown crossing the Egyptian western desert and the Bahariya Oasis, southwest of Cairo, in this picture taken May 15, 2015. Egyptian security forces on Sunday killed 12 Mexicans and Egyptians and injured 10. REUTERS/Amr Abdallah Dalsh

The Mexican government has called for an investigation into the deaths of at least two of its nationals following an attack on a group of tourists by Egypt’s security forces. The attack, which left 12 people dead and at least 10 people injured, occurred Sunday, according to the BBC. Egypt’s interior ministry admitted that the country’s security forces killed 12 people, including a group of Mexican tourists, in a case of mistaken identity.

Mexican President Enrique Peña Nieto strongly criticized the incident. “Mexico condemns these acts against our citizens and has demanded that the Egyptian government conduct an exhaustive investigation of what happened,” he wrote in a post on Twitter.

Egypt’s foreign minister spoke Monday with Mexico’s foreign minister and said the tourists had been in a restricted area. The minister said the Egyptian government would provide medical treatment to victims and aid in the repatriation of bodies back to Mexico, according to the Associated Press.

The incident took place Sunday when four vehicles traveled in the Wahat area of the western desert, in what the Egyptian interior ministry called a restricted zone that was “off limits to foreign tourists.” Egypt’s interior ministry said in a statement that the vehicles were “mistakenly dealt with” in a security operation that involved both military police and armed forces.

A local tour guide who spoke with the BBC denied the government’s claim, insisting the group was not in a restricted area and was in a spot on top of sand dunes. The BBC also cited a local source who said a driver had said that the convoy had a police escort. The BBC was unable to confirm this information.

At least ten Mexicans and some Egyptians were injured in the incident and were being treated at a local hospital. Mexico’s ambassador to Egypt visited the hospital and spoke with five citizens who were reportedly in stable condition. The Mexican government said it was working to confirm the identity of the victims.

Egypt’s interior ministry has claimed that its security forces were pursing Islamist militants at the time of the incident. Egypt has dealt with terrorism and Islamist militants for years, especially with attacks in the country’s Sinai Peninsula. The western desert remains a popular area for tourists to visit.