More than 100 bodies have been found in Ivory Coast, the United Nations has said, amid the continuing conflict between rivals for the presidency.
The UN said the bodies had been found in the west of the country, in apparent ethnic killings.
Internationally recognised President Alassane Ouattara has been battling incumbent Laurent Gbagbo, who is blockaded in a bunker in Abidjan.
Meanwhile, the EU says it may ease sanctions after a plea by Mr Ouattara.
The UN has certified Mr Ouattara as the winner of November’s run-off vote for president but Mr Gbagbo has refused to cede power.
Mr Ouattara’s forces have swept down from the north over the past two weeks but much of the main city of Abidjan is dominated by Gbagbo supporters and days of fighting has plunged it into crisis.
Rupert Colville, spokesman for the UN High Commissioner for Human Rights, said its team had found more than 100 bodies in the past 24 hours across three locations.
“All the incidents appear to be ethnically motivated,” he said.
Mr Colville said 40 bodies had been found in Blolequin, a town west of Duekoue that is now deserted, adding that the “perpetrators appear to be Liberian mercenaries”.
He said: “The team also went to a nearby town of Guiglo, where they saw more than 60 bodies.”
He said some victims had been burned alive and others had been thrown down a well.
The reports of mass killings began last week, after Duekoue was captured by pro-Ouattara forces.
Each side has blamed the other for the killings, which the International Committee of the Red Cross says claimed hundreds of lives.
Mr Colville told the BBC there were fears more bodies would be found.
He added: “If Mr Gbagbo gives up, it would allow the new administration to try to restore law and order but it is very hard for everyone, including the UN, while this impasse continues.”
Mr Colville said of the latest killings that “one has to be a little bit cautious of assigning responsibilities”.
The Ouattara camp has previously accused Laurent Gbagbo of recruiting Liberian mercenaries, a claim Mr Gbagbo denies.
But there are reports of both sides using local ethnic militias, which have had a long-standing influence in the west of the country. They were not disarmed after the previous civil war and their overall loyalty is questionable.
‘Question of principle’
On Friday, UN relief agencies called for humanitarian corridors which will allow safe passage for thousands of people fleeing the fighting.
Meanwhile, the European Union says it hopes to begin easing some of its sanctions on Ivory Coast soon, following a request from Mr Ouattara.
A spokesman for EU foreign policy chief Catherine Ashton told the BBC: “We’ve received a request from President Ouattara to remove certain entities from the sanctions list. We are working on this in close consultation with President Ouattara and hope to be able to begin easing the sanctions soon.”
There are EU sanctions across many sectors, including on two key ports, banks and on cocoa exports, as well as individual sanctions on Mr Gbagbo and dozens of his supporters.
In Abidjan, pro-Ouattara forces continue to besiege Mr Gbagbo in his residence.
Mr Ouattara said a blockade had been set up around the perimeter to make the district safe for residents. He said his forces would wait for Mr Gbagbo to run out of food and water.
Advisers to Mr Gbagbo say he is determined not to surrender.
“President Gbagbo will not surrender,” said his Paris-based adviser Toussaint Alain.
“It’s a question of principle. He is a president elected by his people.”