Mexico has asked Egypt to swiftly investigate why tourists were mistakenly targeted in what witnesses describe as an air strike that left at least two Mexicans dead and six unaccounted for.
President Enrique Pena Nieto said 14 Mexicans were among those involved in Sunday's "grave incident" in the Western Desert.
Egyptian authorities said security forces mistakenly killed 12 people and wounded 10 others when they struck their convoy while chasing fighters, but they have not given details about the weaponry used or the breakdown of victims.
A joint police and military operation on Sunday "chasing terrorist elements" in Al Wahat "mistakenly" targeted four pick-up trucks carrying Mexican tourists, Egypt's interior ministry said in a statement.
Mexico's ambassador to Egypt said six Mexicans were still unaccounted for while a woman and a man were confirmed dead.
The wounded included five women and a man who are in stable condition.
Egyptian authorities said the tourists were in an area that was "off-limits" but did not provide an exact location.
Al Jazeera's John Holman, reporting from Oaxaca in Mexico, said the Mexican government had demanded a thorough investigation into the incident.
"President Enrique Pena Nieto on Twitter condemned the incident," he said.
Speaking at a military event in Mexico City on Monday, Pena Nieto said: "The events of yesterday have saddened us as a nation.
"There is no precedent, in years, of an event like this one that harms our compatriots.
"Mexico has demanded from the Egyptian government an exhaustive, deep and swift investigation into what happened."
Egypt pledged to form an investigative committee that will be headed by Ibrahim Mahlab, the prime minister.
Mona el-Bakri, spokesperson for Cairo's Dar al-Fouad hospital where the wounded are being treated, said two of the seven Mexicans receiving treatment also hold American citizenship.
Six Mexican survivors told the Mexican ambassador that they had stopped for a meal when they "suffered an aerial attack with bombs launched by a plane and helicopters", Claudia Ruiz Massieu, the Mexican foreign secretary, said.
A ministry source later told AFP that the Mexican government had chartered a plane for the families of the victims to head to Egypt on Monday, and that Ruiz Massieu would be joining them personally "to coordinate support efforts".
The group had arrived in Cairo on September 11 and left two days later on their way to the Bahariya oasis, Ruiz Massieu said.
They were near the oasis when they came under fire, she said. The Egyptian travel agency Windows of Egypt informed the Mexican ambassador about the attack.
|Egyptian security forces have been battling an insurgency in the Sinai Peninsula and in the Western Desert [AP]
Her ministry delivered a diplomatic note to the Egyptian ambassador in which the Mexican government expressed its "deep dismay over these deplorable events" and demanded an investigation.
"The Mexican government asks that Egyptian authorities give the highest priority and urgency to clearing up this issue," Ruiz Massieu said.
By late Monday, Jorge Alvarez Fuentes, Mexico's ambassador to Egypt, told local media that two dead Mexican citizens had been identified as Luis Barajas Fernandez and Maria de Lourdes Fernandez Rubio.
A third Mexican citizen, Rafael Bejarano, was confirmed dead by his sister, who said she had been informed of his death by his travelling companions.
Source: Al Jazeera and agencies