Abidjan, Ivory Coast (AP) - Ivory Coast state television disappeared from the airwaves outside the nation's largest city late Thursday, a blow to the incumbent president's attempts to cling to power in the bloody aftermath of an election most of the world says he lost.

Also Thursday, the United Nations recognized incumbent Laurent Gbagbo's challenger, Alassane Ouattara, as the winner of the Nov. 28 runoff vote. The 192-nation U.N. General Assembly rescinded the credentials of Ivory Coast's U.N. Ambassador Ilahiri Djedje, a Gbagbo supporter, and accepted those of Ouattara's choice, veteran diplomat Youssouf Bamba.

The U.N. deputy human rights commissioner in Geneva, Kyung-wha Kang, said at least 173 people had died in violence since the election. She detailed hundreds of arrests and detentions, dozens of cases of torture and mistreatment, and said government forces were preventing investigators from looking into other reports of human-rights violations, including possible mass graves.

The state television channel controlled by incumbent Gbagbo continued to air in Abidjan, but only black and white snow appeared in at least six other cities around the West African nation just minutes before Ivorians sat down to their nightly newscast, residents told The Associated Press.

It was not immediately clear how the signal was cut off. Advisers to Ouattara refused to comment, but the event falls in line with a series of strategies Ouattara has been employing to try to break Gbagbo's stranglehold on the news.