Egyptian security forces mistakenly killed 12 Mexican and Egyptian tourists and guides in the Western Desert, said the interior ministry on Monday.

According to an official statement from the Ministry of Interior, the group of tourists and guides were mistaken for terrorists. This caused Egyptian forces to open fire on the four SUVs carrying the tourists, which resulted in 12 deaths and 10 other injuries.

“A joint police and army force were chasing terrorist elements in the western desert area of Al-Wahat,” read a statement from the Ministry of Interior.

According to statements given to the Middle East News Agency (MENA), the Ministry of Tourism’s spokeswoman Rasha Al-Azayzee said that the group of tourists had passed through a prohibited area.

Al-Azayzee added that the Ministry of Tourism had received no notification of the group’s journey through the desert.

Although – as of yet – the number of Mexicans and Egyptians killed is unclear, Mexico’s Foreign Ministry confirmed that two Mexicans were among those killed.

Following the attack, Mexican President Enrique Peña Nieto tweeted, ““In a tragic incident in Egypt, Mexican tourists were attacked. I deeply regret that people have lost their lives.”

“Mexico’s Ambassador to Egypt has been at the hospital supporting those wounded. Mexico condemns these acts against our citizens and against the Government of Egypt and has called for a thorough investigation of what happened,” he continued.

The Western Desert, which borders Libya, has become increasingly volatile territory.

At least 21 Egyptian soldiers were killed in July 2014 when gunmen attacked a military checkpoint in the Western Desert.

On Sunday, ISIS announced on social media that it had attacked a number of Egyptian military outposts in the Western Desert. Local media stated that the military had managed to cause significant casualties to the terrorist group, however this was not officially confirmed by the military.

Similar attacks on Egyptian security forces in the Western Desert, as well as Sinai and Cairo, have increased in occurrence ever since the ouster of former President Mohammed Morsi in July 2013.

Information gathered from Ahram Online, Reuters and Egyptian Streets.