Honduras' coup-installed government silenced two key dissident broadcasters on Monday just hours after it suspended civil liberties to prevent an uprising by backers of ousted President Manuel Zelaya.

Dozens of soldiers raided the offices of Radio Globo. Officials also shut down Channel 36 television station, leaving it broadcasting only a test pattern.

Rene Zepeda, a spokesman for the interim government, said the two outlets had been taken off the air in accordance with a government emergency decree announced late Sunday that limits civil liberties and allows authorities to close news media that "attack peace and public order."

Supporters of the deposed leftist president vowed to march in the streets Monday in defiance of the emergency order and carry out what Zelaya calls a "final offensive" against his ouster on the three-month anniversary of the coup.

"They took away all the equipment. This is the death of the station," said Radio Globo owner Alejandro Villatoro, describing the dawn raid on the station.

Station employees scrambled out of an emergency exit to escape the raid that Villatoro said involved as many as 200 soldiers.

He said the office remained surrounded by soldiers. It was the second time soldiers have barged into the station — the first was June 28, the same day Zelaya was ousted.

The interim government has long argued it is trying to preserve democracy in Honduras, and even cited the fact that pro-Zelaya media such as Channel 36 were operating freely as proof.

But the emergency decree showed a tough new stance domestically and internationally, a reversal from last week, when interim President Roberto Micheletti indicated his administration was willing to hold talks with Zelaya, who has taken shelter at the Brazilian Embassy after sneaking into the country a week ago.

The Organization of American States in Washington called a high-level emergency meeting on Monday to discuss the Honduras crisis after the interim government expelled at most members of an OAS advance team that had arrived Sunday to try to restart negotiations.

Micheletti's Foreign Minister Carlos Lopez said the team had not given advance warning of its arrival and said it did not come "at the right time ... because we are in the middle of internal conversations."

Officials also issued an ultimatum to Brazil on Sunday, giving the South American country 10 days to turn Zelaya over for arrest or grant him asylum and, presumably, take him out of Honduras.

Lopez said Brazil had broken relations by withdrawing its ambassador and said if it does not restore ties, the diplomatic mission would become a private office — implying it could be raided by police.

Brazilian President Luiz Inacio Lula da Silva responded, saying that his government "doesn't accept ultimatums from coup-plotters."

Micheletti has pledged not to raid the embassy where Zelaya has been holed up with more than 60 supporters.

The building is surrounded by armed police and soldiers, who have been there since baton-wielding troops used tear gas and water cannons to chase away thousands of his backers when he returned to the country Sept. 21.

Protesters say at least 10 people have been killed since the coup, while the government puts the toll at three.

The government's suspension of civil liberties limits rights guaranteed in the Honduran Constitution: The decree prohibits unauthorized gatherings and allows police to arrest without a warrant "any person who poses a danger to his own life or those of others." It also allows officials to shut down media outlets for "statements that attack peace and the public order, or which offend the human dignity of public officials, or attack the law."

The Honduran Constitution forbids arrests without warrants except when a criminal is caught in the act.

In a nationally broadcast announcement, the government explained it took the steps it did "due to the calls for insurrection that Mr. Zelaya has publicly made."

Zelaya is demanding to be reinstated and has said that Micheletti's government "has to fall."

While many nations have announced they would send diplomatic representatives back to Honduras to support negotiations, the interim government said Sunday that it would not automatically accept ambassadors back from some nations that withdrew their envoys.