Mexico City, Sep 16 (IANS): Mexican President Enrique Pena Nieto speaking with his Egyptian counterpart Abdel-Fattah al-Sisi reiterated Mexico's call for a "swift and in-depth" investigation to determine who was responsible for shelling the group.

Pena Nieto over the phone on Tuesday expressed "Mexican society's pain and indignation" at the accidental killing of eight nationals visiting Egypt, reported Xinhua news agency.

He asked Sisi to fully support his government, including aiding Mexico's Foreign Affairs Minister Claudia Ruiz Massieu, who flew to Cairo on Monday accompanied by family members of the victims.

Sisi telephoned Pena Nieto to express his condolences and his willingness to provide the injured with the aid they need and help the Mexican minister with her mission, as well as launch an investigation into the incident.

Egyptian military troops reportedly pursuing anti-government guerrillas shelled the group on Sunday when they travelled aboard four vehicles through the western desert, an area popular for its sand dunes and verdant oases.

The area is currently a restricted zone off-limits to civilians, but the group's travel agency had secured the necessary permit.

In July 2014, at least 21 Egyptian soldiers and several others were injured in an attack by anti-government rebels in the western desert's Al Farafra Oasis.

Egypt has seen the number of attacks against government forces increase, especially in the Sinai region, since the army ousted democratically-elected President Mohamed Morsi, a member of the Muslim Brotherhood.