The International Committee of the Red Cross (ICRC) said on Sunday that they evacuated about 30 wounded to the local hospital in addition to the eight people killed.
ICRC spokesman Kim Gordon-Bates said: "The situation there at the moment is still tense and we're keeping a close watch on it."
Residents said on Saturday that hundreds of people had fled their homes after their houses were attacked and looted by members of a rival ethnic group. Many sought shelter at a Catholic mission in the town.
"It's full here. It's difficult to get out of the building," said Father Francois Ubach, who has worked as a Spanish missionary in Ivory Coast for over two decades. He estimated as many as two thousand people may have left their homes.
Residents said they heard gunfire early on Sunday but the situation now appeared to be calm.
The attacks were triggered after members of the Guere community, which hails from Ivory Coast's west, returned to work on Friday despite a call for traders and transport workers to strike over security problems in the town, locals said.
The area around Duekoue is an ethnic tinderbox where a civil war which erupted in 2002 has exacerbated long-running disputes between local villagers and farmers from neighbouring countries or other parts of Ivory Coast.
"The situation there at the moment is still tense and we're keeping a close watch on it"
A ceasefire agreement was signed in May 2003, but the world's top cocoa grower is still split between a government-run south and rebel-held north.
UN peacekeepers based in Duekoue - part of an international force that helps police the buffer zone dividing the country - said on Saturday that calm had been restored but gave no further details.
A senior Ivorian army officer said his colleagues had fired warning shots to help calm the situation.
After years of sporadic fighting and failed peace deals, there have been signs of progress in efforts to end the conflict in Ivory Coast.
Rebel and government forces have started pulling back heavy weapons from front lines as part of a peace deal signed in South Africa last month, and have also pledged to study proposals for starting full disarmament in May.
President Gbagbo says his main
rival can run in October's election
President Laurent Gbagbo has said he will allow his main opposition rival, Alassane Ouattara, to stand in elections on 30 October, a key demand of the rebel forces.
Ouattara's exclusion from a 2000 poll because of doubts over his nationality was seen as one of the root causes of a war that has crippled one of the region's economic powerhouses and threatened to spread turmoil to fragile neighbouring states.