Three United Nations peacekeepers were killed while two have been severely injured in an attack by unidentified gunmen in the Central African Republic, UN Secretary spokesperson Stephane Dujarric on Friday.

According to a report by Agence France Presse the announcement was made after a "rebel coalition fighting the government called off a ceasefire ahead of a tense general election due to take place Sunday".

UN Secretary-General Antonio Guterres condemned the attack by unidentified armed combatants. "The Secretary-General expresses his deepest condolences to the families of the deceased peacekeepers, as well as to the people and Government of Burundi. He wishes a speedy recovery to the injured," the statement read.

The Secretary-General also recalled that attacks against United Nations peacekeepers may constitute a war crime, ANI reported. He called on the Central African Republic authorities "to investigate these heinous attacks and swiftly bring perpetrators to justice".

Central African Republic has been unstable ever since its independence 60 years ago and is the second poorest nation globally.