The UN's human rights chief in Ivory Coast has told the BBC new mass graves have been found there containing the remains of more than 50 male victims.
Guillaume Ngefa said two burial sites had been found in a suburb of Abidjan.
He said local people allege that many of the victims were killed by former President Laurent Gbagbo's supporters.
They said the massacre in the Yopougon district happened the day after Mr Gbagbo was seized by supporters of his opponent, President Alassane Ouattara.
Mr Ngefa said the UN was examining all mass graves, including those alleged to contain the bodies of Mr Gbagbo's supporters.
He said that so far 10 graves had been found in Abidjan with a total of 63 bodies.
"We suspect there could be more," he told the BBC's World Today programme.
One of the suspected mass grave sites is at a football pitch in Yopougon, which was controlled by pro-Gbagbo groups until last week.
Mr Ngefa said the evidence found could be used by either national or international teams investigating alleged human rights abuses during the four-month dispute.
Last month, UN investigators found at least 200 bodies in a mass grave in the western Ivorian town of Duekoue.
In January, as the political violence escalated, UN high commissioner for human rights Navi Pillay said Gbagbo loyalists had denied her officials access to three mass graves in the country.
Mr Ouattara, Ivory Coast's internationally recognised president, was sworn in last week.
Mr Gbagbo's refusal to cede power after losing a November election sent the nation close to repeat of its 2002-03 civil war.
He is now under house arrest and is being investigated for alleged human rights abuses.
Some 3,000 people are believed to have been killed during the unrest in the world's largest cocoa producer, previously one of West Africa's richest countries.