The interior ministry of Egypt has reported that during an anti-terror operation security forces mistakenly killed 12 innocent tourists, among them Mexican tourists.

According to sources at the BBC, eight of the dozen killed were Mexican citizens, although the Guardian puts the number at a more conservative two.

The ministry explains the killings occurred when the tourists, who were travelling in four vehicles, entered into a restricted zone in the Wahat area of the Western Desert.

Aside from the 12 now dead, 10 others were injured.

Mexico's President Enrique Peña Nieto has called for “an exhaustive investigation by the Egyptian government."

The Mexican foreign ministry said on Monday Mexico's ambassador to Egypt had gone to the local Dar-el-Fouad hospital and spoken to six Mexicans citizens who are said to be in stable condition. They described helicopters and aircraft attacking the convoy.

The Mexican Foreign Ministry has so far confirmed the deaths of at least two of its citizens, stating that the ambassador had been informed of the incident by the tourism company, Windows of Egypt.

“Unfortunately, we have confirmed the deaths of two Mexicans. We are confirming the identities of other possible victims,” Claudia Ruiz Massieu, Mexico’s Secretary of Foreign Affairs, wrote on Twitter.

Jorge Alvarez, the Mexican envoy to Cairo, wrote on his Twitter account that: “The Embassy of Mexico is providing all consular support to victims of the attack Mexican tourists in Egypt."

A spokesman for the Egyptian tourism ministry says that the tour group did not have the right permits to be in the restricted area, and thus they were there illegally.

The Interior Ministry assures that, “A working group has been formed to examine the causes and circumstances of the incident as well as the justification for the presence of a tourist group in a region to which access is prohibited”

The tourists had been preparing to camp out in the Western Desert when they came under fire.