Militants are planning to mark the 100th anniversary of Ireland’s Easter Rising against British rule with attacks on police and army targets in Northern Ireland, the province’s police force warned on Friday.

Militants are planning to mark the 100th anniversary of Ireland's Easter Rising against British rule with attacks on police and army targets in Northern Ireland, the province's police force warned on Friday.

The warning came just hours after a 52-year-old prison officer was injured when an explosive device detonated under the van he was driving shortly after leaving his home in Northern Ireland's main city, Belfast.

Stephen Martin, a senior officer in Northern Ireland's police force said he was "very worried" about the threat ahead of the commemoration on March 27 of the revolt that paved the way for Ireland's independence.