The Honduran government government cut off electricity to the Brazilian embassy where ousted President Manuel Zelaya is hunkered down, a senior State Department official told ABC News, and the United States is trying to ease tensions, and to get a generator for the the blacked out embassy.
Zelaya sought refuge in the embassy after he snuck into the country on Monday in defiance of the de facto regime, which has ordered his arrest.
Roberto Micheletti, who replaced Zelaya as president, has pressured Brazil to turn over Zelaya to Honduran authorities, on a warrant issued by the country's supreme court charging him with treason and abuse of authority.
The United States is urging calm and respect for the diplomatic immunity of the Brazilian embassy in Tegucigalpa, the Honduran capital.
"The United States calls on all parties to remain calm and avoid actions that might provoke violence in Honduras and place individuals at risk or harm," State Department spokesman Ian Kelly said. "We urge that all parties refrain from actions that would lead to further unrest."
In New York City, where world leaders gathered at the United Nations for a climate conference, Brazilian Foreign Minister Celso Amorin told reporters that Brazil will not allow any actions to be taken against its embassy in Tegucigalpa.
He also said the Latin American giant may ask the U.N. security council for an emergency meeting to discuss the safety of its diplomatic mission in Honduras.
Zelaya's surprise return has touched off a wave of violence and repression.
Clashes between hundreds of his supporters camped outside the Brazilian embassy and security forces have resulted in at least 200 arrests, and many injured, according to El Heraldo, one of Honduras' leading newspapers.
In an email, David Brown, who is serving as a volunteer in the Central American nation, told ABC News: "[The military] have shut down the entire country. We are on indefinite curfew, meaning anyone outside of their home is subject to immediate arrest. They have cut electricity to various parts of the city. They have closed the borders and airports. They have forced the opposition media outlets off the air and off the web."
Micheletti told the international community that his government is open to dialogue.
He also denied that the military will storm the Brazilian embassy to forcibly remove Zelaya.