The 15-member council unanimously adopted a presidential statement stating that it "considers this aggression to be an unacceptable outrage".
The eight peacekeepers, from the Guatemalan special forces, were involved in a firefight with suspected elements of the Lord's Resistance Army (LRA) in DRC's Garamba Park on Monday.
Five other UN soldiers were injured in the gun-battle and were evacuated several hundred kilometres to Bunia, the chief town in the lawless Ituri district in Orientale Province where the UN’s DRC mission, MONUC, operates a military base.
The LRA has waged a bloody war in northern Uganda since 1988, ostensibly to replace President Yoweri Museveni's government with one based on the biblical Ten Commandments.
The LRA became well-known for its brutality toward civilians, tens of thousands of whom have been killed and some 1.6 million of whom have fled their homes fearing attacks.
The statement -- read by the Security Council’s president for January, Tanzania's UN envoy Augustine Mahiga -- also firmly condemned the recent seizure of villages in the area of Rutshuru, in DRC's Kivu province, by insurgents and expressed concern about "atrocities and human rights abuses which have been reported in this context."
It stressed the need "for unreserved commitment to the integration process of the armed forces" and underlined "the importance for the electoral process not to be disturbed."
More than 20 million people have registered to vote in DRC's legislative, presidential and local polls set for June 30, the first for more than 40 years in the former Zaire.
DRC has been ruled by President Joseph Kabila's interim government since a 2003 peace accord ended a five-year civil war.
The council also reiterated its appeal to regional countries to step up their cooperation to end the activities of illegal armed groups and reaffirmed its support for the MONUC.