The deaths of two Mexicans had earlier been confirmed, bringing the total number of Mexicans killed to eight.
Six other Mexicans were injured in the attack. The department said today their condition is stable. There were 14 or 15 Mexicans who traveling on a desert oasis tour at the time.
Egyptian forces hunting militants in the country's western desert mistakenly opened fire on several vehicles used by Mexican tourists, killing 12 people on Sunday.
Foreign Relations Secretary Claudia Ruiz Massieu called the aerial attack "an unjustified aggression."
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The sister of one of the Mexican tourists killed said her brother, Luis Barajas Fernandez, 49, had been visiting Egypt for the first time.
"He had never gone to Egypt before," said Ana Barajas, who lives in the northern Mexico state of Tamaulipas.
"It was for pleasure," she said of the trip.
The married 49-year-old had worked as a salesman in hospital and medical supplies.
"It is an unparalleled hurt," she said of his death, adding the Mexican government was going to take care of the response to her brother's death, and the repatriation of his remains.
Two other Mexican dead have been identified by name as Maria de Lourdes Fernandez Rubio and Rafael Bejarano.
The incident, among the deadliest involving tourists in Egypt, comes as the country is trying to revive its vital tourism industry after the turmoil following the 2011 uprising that toppled President Hosni Mubarak.
Egypt has mainly been battling insurgents in the northern Sinai Peninsula, on the other side of the country, where Islamic militants stepped up attacks on security forces after the military ousted Islamist President Mohammed Morsi in 2013 amid massive protests against his rule.
Egyptian officials claimed the safari convoy had wandered into a restricted area. The tour company involved "did not have permits and did not inform authorities," Rasha Azazi, a spokeswoman for the Egyptian Ministry of Tourism, told The Associated Press, adding that any trips to that area must be cleared by officials.