CAIRO: Cairo International Airport authorities today declared an emergency and took measures to secure planes after receiving a UN plane bomb threat from an unknown person demanding 20 million EGP (U.S. $3.3 million). An officer in the airport this morning received a phone call demanding 20 million EGP or a UN plane bound for Hall 4 at the airport would be destroyed, security sources said. The UN plane is used in humanitarian relief efforts, mostly, particularly for refugee affairs and food distribution. An emergency alert was sounded and an explosives team was dispatched to check the private jets. No explosives were discovered.