Berlin - German Foreign Minister Frank-Walter Steinmeier expressed concern Tuesday following the previous night's murder of a police officer in Northern Ireland.

Of the shooting, which claimed the third victim within 48 hours in a new wave of terrorist violence in Northern Ireland, Steinmeier told journalists it gave him cause for "great concern."

It was important, Steinmeier said, that those involved in the negotiations aimed at stabilising the region didn't back off. He further hoped that the security forces were able to get the situation back under control.

A dissident Irish Republican group, Continuity IRA, on Tuesday claimed responsibility for the murder of 48-year-old police Constable Stephen Carroll.

The organisation is a splinter group of the former Irish Republican Army (IRA).

Forty eight hours previously, two British soldiers had been gunned down at an army barracks north of Belfast Saturday.

Another dissident group, the Real IRA, claimed responsibility for that attack, in which two soldiers and two civilians were also seriously injured. (dpa)