A four-member crew of military officers, two Egyptian and two Emirati, were killed Wednesday when their aircraft crashed during a joint drill, Egypt's army and a UAE report said.
The crash occurred in Egypt, the UAE's official news agency WAM said.
The downing was caused by a technical malfunction, the Egyptian military said in a statement, without elaborating.
Authorities of both states were investigating the accident.
In August, reports surfaced that the governments of the two close Arab allies allegedly carried out air strikes against Islamist militias in the Libyan capital, Tripoli, with Egypt repeatedly denying any involvement in Libya's affairs.