The RUC discovered the component parts for 14 pipe bombs and several rounds of ammunition at the rear of flats in a loyalist area of Lurgan yesterday.
Shortly after midday, police moved into an area of Portlec Place in the loyalist Mourneview estate. Part of the road was cordoned off as they carried out an extensive search of the immediate area. A number of homes were evacuated after officers discovered the pipe bombs in a shed at the rear of some flats.
The Northern Secretary, Dr Mo Mowlam, was urged to review the Loyalist Volunteer Force ceasefire after the pipe bombs were found.
One man was arrested in connection with the find.
Police have described the find as "very significant", although they have stressed that the devices are not of the same type as the one used to kill Mrs Elizabeth O'Neill in Portadown last Saturday morning. The pipe bombs are of a much older design and are believed to have been in the shed for some considerable time.