The US State Department said on Monday it was looking into reports suggesting a US national was injured when Egyptian security forces mistakenly attacked a tourist convoy made up mostly of Mexicans on Sunday.
Twelve people were killed and 10 injured when Egyptian security forces attacked four 4x4 vehicles in what officials said on Monday is a "restricted area" near the Bahariya oasis, a tourist attraction in the western desert.
Earlier on Monday tourism minister Khaled Ramy had said one of the injured was American, Al-Ahram Arabic news website reported.
Egyptian prosecutors and judicial sources said seven of those killed in the incident were Mexican and four Egyptian. Mexican president Enrique Pena Nieto confirmed on Monday at least two Mexicans had been killed.
State Department spokesman John Kirby told a regular press briefing on Monday that the US embassy in Cairo is making "appropriate inquiries" with Egyptian police about reports that a US citizen might have been wounded in the accident.
Kirby did not want to give more details before investigations by the Egyptian authorities are concluded.
"We need to let the investigation go forward," he said.
But Kirby said the matter is still being probed.
"We have to let the investigation proceed before we jump to any conclusions about exactly what happened and what the circumstances were, or what hardware was involved."
When asked whether Egyptian authorities are using excessive force in their fight against militants in the northern part of Sinai [and if this could be a reason behind Sunday's mistaken attack on the convoy], Kirby said it is "premature and speculative" to link the accident with the use of force against militants [in Sinai].