A senior RUC officer has said the explosives found yesterday following a planned search of countryside near Dungiven, Co Derry, were a danger to the public even though it was believed they had been hidden for years. Supt Noel McClenaghan said he believed the Mark 16 mortar, which was found with 180 lb of home-made explosives, two time power units, a warhead and a firing tube, belonged to the Provisional IRA.