Analysis: Frank Gardner, BBC Security Correspondent
The disastrous shooting up by Egyptian security forces of a tourist convoy in the Western Desert is yet another sign of growing instability in the Arab world's most populous country. Egypt's western oases - Bahariya, Dakhla, Kharga and Farafra - are spectacularly beautiful, hence their popularity with today's adventure tourists.
But since the Arab Spring upheavals of 2011, security along Egypt's border with Libya has deteriorated as the Islamist insurgency has grown across the country. Vast stretches of both the Sinai Peninsula and the Western Desert are now too dangerous for Westerners to visit.
Last month IS militants beheaded a Croatian engineer they had kidnapped not far from Cairo. Now the possibility of being mistakenly shot at by the authorities, as well as being kidnapped by militants, will further damage Egypt's much depleted tourism revenues.