The bomber, an unidentified man, set off the explosion around 8pm local time at the entrance to the busy bar in Ishango.
In a statement, the government of President Félix Tshisekedi pointed the finger at Islamist terrorism.
The attack has sparked a wave of reactions. Huang Xia, the UN Secretary-General's Special Envoy for the Great Lakes Region, said he "strongly condemns the cowardly attack in Beni."
The death toll from a Saturday suicide bombing attack on a restaurant in Beni city, Democratic Republic of Congo, has risen to eight.
The Christmas Day attack happened at Inbox bar where people were celebrating the festive season.
The bomber, an unidentified man, set off the explosion around 8pm local time at the entrance to the busy bar in Ishango.
It is not yet clear if the suicide bomber was acting alone or part of a group, but this is the third bomb attack in Beni since June.
In a statement, the government of President Félix Tshisekedi pointed the finger at Islamist terrorism. Officials said the crimes will not go unpunished and that the perpetrators will be hunted down.
The attack has sparked a wave of reactions. Huang Xia, the UN Secretary-General's Special Envoy for the Great Lakes Region, said he "strongly condemns the cowardly attack in Beni."
"We stand united with the Congolese people and government in this moment of grief and mourning. Our support for the DRC and the region's fight against armed and terrorist groups remains unwavering".
"Eight compatriots are dead and 20 wounded. Security measures reinforced, curfew at 19h00," said Patrick Muyaya, spokesman for the Congolese government.
Among the dead was a Congolese army officer, his wife and child.
Mr Muyaya said the mayor of Rwenzori commune and the deputy mayor of Mulekera commune were among the injured.
