A "significant" amount of bomb-making components and explosives has been found at a country park around 25 miles north of Belfast in Northern Ireland, police said on Sunday.
On Friday a prison officer was injured by a bomb which exploded under his van in Belfast, prompting police to warn of a "severe" threat to security forces as the centenary approaches of the 1916 anti-British Easter Rising.
A 1998 peace deal largely ended three decades of violence in Northern Ireland between Protestants who want to remain under British rule and Catholics favouring a united Ireland, but violence sporadically erupts.
"Police have uncovered a significant terrorist hide containing bomb-making components and explosives at Carnfunnock Country Park," the Police Service of Northern Ireland said in a statement.
"A number of small plastic barrels had been buried in a wooded area. Inside the barrels was a significant amount of bomb-making components including partially constructed devices and a small quantity of explosives."
Police said the haul was discovered after a member of the public reported a suspicious object on Saturday.
Detective Chief Inspector Gillian Kearney said it was too early to link the items to any particular group, but they were undergoing detailed examination.