Explosive parts have been found in woodland in Co Antrim, police said.
The discovery at Capanagh Forest near Larne comes two months after bomb-making items were found at nearby Carnfunnock Country Park.
Detectives are investigating whether the finds are linked.
Police said the items were discovered by two members of the public on Saturday.
The items have been taken away for further forensic examination.
Detective Inspector Adrian Brown from the Police Service of Northern Ireland’s Serious Crime Branch said: “This investigation is at a very early stage and we are working to establish whether this find is linked to a terrorist hide that was discovered at Carnfunnock country park near Larne in March 2016.
“I would ask the public to remain vigilant wherever they are and whatever they are doing.
“If you see any suspicious activity, or have seen anything unusual in this area, please contact police so that we can act on the given information.”