A pipe-bomb and component parts for two other devices have been found during police searches of houses in Ballymena, Co Antrim, yesterday.A sawn-off shotgun and an automatic pistol were also recovered.
In Maghera, Co Derry, two blast-bombs were made safe by British army bomb disposal experts on Wednesday night.
The security alert began when technical officers were sent to the Mullagh Lane area of the town following a telephone warning that a bomb had been left in the area.
Part of Maghera was sealed off during the security operation, while officers made safe the two blast-bombs which were then taken away for forensic examination.
A PSNI spokesman said that at this stage there did not seem to be a sectarian motive behind the existence of the two devices.
"Although the motive is still unclear, it is not believed to be sectarian," he said.
He also appealed for anybody with information on the bombs to come forward.
Meanwhile, shotgun cartridges and other ammunition have been found in the Clogh area of Co Antrim.
No arrests were made and police are continuing their inquiries.