LONDON, Nov 12 (Reuters) - An outbreak of bird flu has been confirmed at a turkey farm in eastern England although the exact strain is not yet known, Britain"e;s farm ministry said on Monday.

The ministry said preliminary results from the farm on the border of Norfolk and Suffolk were positive for the H5 strain but it is not known if it is the deadly H5N1 variety which has swept across Asia, Europe and Africa during the last couple of years.

All the birds at the farm will be culled and protection and surveillance zones are being set up. (Reporting by Nigel Hunt; Editing by David Evans)