Geneva: United Nations Secretary-General Ban Ki-moon has condemned the alleged attack on a Russian plane in "the strongest terms" and voiced his deep sadness for the victims of the crash in Egypt's Sinai earlier on Saturday.

Ban told a group of journalists here on Saturday afternoon that he has received the report that the Islamic State (IS) claimed responsibility for the crash of a Russian plane, saying it is a complete crime to target civilian airlines and a full investigation should be carried out as soon as possible.