Ian Hendry as Col Tom Llewellyn

Alan Badel as Dr. David Neville

Barbara Ferris as Susan Eliot

Alfred Burke as Colin Webster

Clive Powell as Paul

Yoke-Moon Lee as Mi Ling

Roberta Rex as Nina

Gerald del Sol as Aga Nagalo

Mahdu Mather as Rashid

Frank Summerscale as Mark Robbin

Sheila Allen as Diana Looran

Ralph Michael as Minister of Defense

Martin Miller as Prof. Gruber

Patrick Wymark as Commander

Harold Goldblatt as Harib

Bessie Love as Mrs. Robbin

Tom Bowman as General Miller

Andre Mikhelson as

Peter Thompson as

Patrick White as Mr. Davidson

Jack Berg as

Eddie Boyce as

Ian Cullen as

Joe Dunne as

Ernest Fennemore as

Patrick Halpin as

Philip Johns as

Annette Kerr as

Arnold Lee as

Martin Lyder as

Frank Maher as

Terence Maidment as

Richard Marner as

Leo McKern as

Tony O'Leary as

Bill Rayment as

Michael Robbins as