Britain's counterintelligence agency has raised the terror threat level in Northern Ireland from "significant" to "high", meaning an attack is highly likely these days.

The British Secretary for Northern Ireland, Chris Heaton-Harris, wrote to MPs in London about the alarm, and told citizens "not to be alarmed, but to remain cautious".

The MI5 alert is linked to the assassination of senior police detective John Caldwell, who remains in a critical condition. On February 22 in Omaha, Detective Caldwell was shot by masked gunmen while he was waiting for his son from football practice. The assassination of the detective, as well as the bombing in Strabane in November, was claimed by the renegade republican group the New IRA. 13 people have been detained, but no one has been charged.

- In the past 25 years, Northern Ireland has transformed itself into a peaceful society. The Belfast Agreement demonstrates how beneficial peaceful and democratic politics are to society. However, a small number of people are determined to harm our communities through politically motivated acts of violence. Over the past few months, we have witnessed a rise in the level of terrorism-related activities, targeting police officers serving their communities, and endangering children and other community members. Such attacks have no support, as evidenced by the reactions to the disgusting attempt to kill Detective Caldwell - Heaton-Harris states in the letter to the deputies.

Less than a year ago, the terrorist threat level in Northern Ireland was lowered for the first time in 12 years after the activities of the New Era subsided. In 2019, journalist Lira McKee was murdered, and in 2012 and 2016, prison guards David Black and Adrienne Ismay were murdered. The New Ira group was formed in 2012 by the merger of two dissident groups from the former Irish Republican Army. Arm na poblacht (Army of the Republic), another group that has not been active until now, threatened several weeks ago to target police officers and their families.

Michelle O'Neill, leader of Sinn Féin's Stormont group, said that "in a modern democratic society there is no place for paramilitary groups: 'They have to go!'".