BELFAST Northern Ireland's police force accidentally shared the names and work locations of every member of staff on Tuesday in a data breach it said would be of "significant concern" to officers who are often targeted by militant groups.

The surnames, initials, work location and department of each staff member were included in error in response to a freedom of information request. The information was publicly available on the requestor's website for around two-and-a-half hours before being removed, the Police Service of Northern Ireland said.

There is nothing at the moment to suggest any immediate concerns to individuals' security, Assistant Chief Constable Chris Todd told a press conference.

However, officers' data is especially sensitive in Northern Ireland as many "go to great lengths and do everything possible to protect their police identity and role," the Police Federation for Northern Ireland, the representative body for officers, said in a statement.

"It is limited to surname and initial only, but that will be still of significant concern for many of my colleagues, I know that, and we will ensure we will do everything we can to mitigate any security risks that are identified," Todd said.

Britain's MI5 intelligence agency increased the threat level in Northern Ireland from domestic terrorism to severe - meaning an attack is highly likely - after an off-duty officer was left seriously wounded in February following a gun attack by the new IRA, one of the small militant groups opposed to peace.

While a 1998 peace deal largely ended three decades of sectarian violence in Northern Ireland, police officers are still sporadically targeted by dissident groups in bomb and gun attacks.

(Reporting by Amanda Ferguson in Belfast; Writing by Padraic Halpin; Editing by Matthew Lewis)