'Bomb': 3 men held.
Police said the incident was not linked to terrorism. The arrests were made in Cwmparc, near Treorchy, South Wales, after a tip off from a member of the public.
Officers later searched four houses in the area.
Chief Supt Jeff Farrar said: "We know that in the current climate this will cause some alarm but we want to reassure everyone that there is no apparent danger and they should not jump to conclusions. "We are not looking for anyone else in connection with this matter."