Paramedics (top) carry the stretcher of a Mexican tourist, who was injured during an attack in Egypt, to a platform from a plane, after their arrival to the presidential hangar in Mexico City, September 18, 2015.

The bodies of eight Mexican tourists killed by mistake in an Egyptian air raid will return home Tuesday, authorities said, amid ongoing diplomatic discord over the incident.

The tourists were killed along with four Egyptians on September 13 when they came under fire during a lunch break in Egypt’s vast Western Desert while on their way to the Bahariya oasis.

Six other Mexicans who were wounded in the attack returned home last week and were treated in a Mexico City hospital.

The foreign ministry said in a statement that the bodies would arrive in Mexico City late Tuesday.

The ministry reiterated that the Mexican government will monitor “the development of the investigation being conducted by Egyptian authorities to clear up this terrible event.”

President Enrique Pena Nieto expressed his outrage at the incident in a phone call with Egyptian President Abdel Fattah al-Sisi last week and dispatched his foreign minister to Cairo to press for a full investigation.

Cairo has promised a full and “transparent” inquiry, although media in Egypt have been banned from publishing any details on the incident or the investigation.

Survivors say they were bombed by an airplane and a helicopter. Egyptian authorities say the tourists were mistakenly killed when security forces were chasing jihadists, but they have not given many details about the operation.