Security forces loyal to Ivory Coast's incumbent president Laurent Gbagbo have launched an offensive in the Abidjan stronghold of his rival, Alassane Ouattara.
Officials said troops attacked the Abobo neighborhood Saturday on the ground and with air support.
A United Nations spokesman said a staff member had been injured by pro-Gbagbo youth who attacked him and burned his car. But speaking to the Reuters news agency, the spokesman downplayed Saturday's violence, saying it was just skirmishes.
The neighborhood has seen ongoing violence since Ivory Coast's November 28 election, which Mr. Gbagbo insists he won, despite U.N.-certified results showing Mr. Ouattara received the majority of the vote.
The U.N. said prior to Saturday's attack that fighting between Gbagbo and Ouattara supporters has killed at least 365 people and displaced nearly 500,000 others.
Reports Saturday did not give details on new casualties.