(Reuters) - U.N. workers in Ivory Coast have found the bodies of more than 100 victims of brutal killings, a discovery that threatened to undermine presidential claimant Alassane Ouattara as he seeks to take control of the country.Ouattara's rival, Laurent Gbagbo, meanwhile was left isolated behind a military cordon in the bunker where he has sought refuge after a concerted assault by Ouattara's troops earlier this week.Read More... More on Laurent Gbagbo