There is a "very dangerous and unpredictable" terrorist threat in Northern Ireland, an independent report into national security has found.
Lord Carlile, formerly the Government's reviewer of terrorism legislation, said he was happy that the security services and Police Service of Northern Ireland were working well together but there remained a "challenging and variable environment".
The annual report also said there had been "some very serious incidents" last year, including the murder of prison officer David Black, shot dead in Co Armagh in November.
The report will not be published because it would breach national security, Northern Ireland Secretary Theresa Villiers said.
The Liberal Democrat peer's findings into the way national security matters are handled in Northern Ireland covered from November 2, 2011, until December 11, 2012, Ms Villiers added in the written ministerial statement to parliament.
She said: "Lord Carlile is briefed by both the PSNI and the Security Service for the purpose of his reports; he states that he is satisfied that the briefings he has received have been full and not selective.
"He states that the Security Service and the Police Service of Northern Ireland work well together and clearly in the national interest.
"Lord Carlile reports that the level of terrorist activity appears broadly similar to that of the previous year; it remains a challenging and variable environment for the PSNI and Security Service.
"He notes the very serious incidents which took place in 2012, including the murder of David Black on November 1 and states that the overall picture is of a very dangerous, unpredictable terrorist threat."