CAIRO Egypt's highest security body warned Sunday that the clock is ticking for a peaceful end to the standoff over sit-ins by supporters of ousted President Mohammed Morsi, suggesting that authorities will break up the protests unless mediation efforts produce results soon.
More than a month after the military overthrew Morsi, thousands of the Islamist leader's supporters remain camped out indemanding his reinstatement. Egypt's military-backed interim leadership has issued a string of warnings for them to disperse or security forces will move in, setting the stage for a potential showdown.
CBS News correspondent Clarissa Ward reported that helicopters had dropped thousands of leaflets onto the crowds of one of the crowds in Cairo. The fliers were from the interior ministry and urged the protesters to go home, promising them a safe exit and saying they understood they have been brainwashed.
But the crowd at the protest camp appeared to be growing, not diminishing, Ward reports. Men ripped the leaflets in front of news cameras, throwing the pieces of paper into the air. The fliers didn't give a deadline by which the protesters have to leave, but it's fair to say many Egyptians are increasingly impatient and that the window for dialogue is rapidly closing.
Also Sunday, authorities announced that a court case accusing the spiritual leader of the Muslim Brotherhood and his powerful deputy of inciting violence will start Aug. 25. Morsi hails from the Brotherhood.
Senators John McCain, R-Ariz., and Lindsay Graham, R-S.C., will arrive in Egypt Monday in an attempt to broker a settlement between Morsi's supporters and the military-back government. They hope to avoid athat has killed more than 250 people -- at least 130 of whom were pro-Morsi protesters shot dead by security forces - since the .
U.S. Deputy Secretary of State William Burns. He extended his visit to Cairo by one day so he could meet military leader Gen. Abdel-Fatah el-Sissi and the country's prime minister on Sunday, an Egyptian Foreign Ministry official said.
While diplomats raced to find a compromise, the Egyptian interim government signaled that its patience with the pro-Morsi sit-ins was running out.
The National Defense Council, which is led by the interim president and includes top Cabinet ministers, said the timeframe for any negotiated resolution should be "defined and limited." The council also said any negotiated resolution would not shield from legal proceedings what it called "law-breakers" and others who incite against the state.
The group called on the protesters to abandon the sit-ins and join the political road map announced the day of Morsi's ouster.
With the Islamist-backed constitution adopted last year suspended and the legislature dominated by Morsi's supporters dissolved, the road map provides for a new or an amended constitution to be put to a national referendum later this year and presidential and parliamentary elections early in 2014.
In a move that underlined the government's resolve in dealing with the protests -- now in their second month -- Egyptian authorities denied Yemen's Nobel Peace Prize winner Tawakkul Karman entry into Egypt after she landed at Cairo airport on Sunday.
Karman, the first Arab woman to win the Nobel Peace prize, has stated her opposition to Egypt's military coup and said she had intended to join the pro-Morsi sit-in protests. She won the prize for her role in protests in Yemen in 2011 that forced longtime dictator Ali Abdullah Saleh from office.
Airport officials did not say why she was denied entry, only that her name had been placed by various security agencies on an airport stop list. The officials spoke on condition of anonymity because they were not authorized to brief the media.
The decision to bar Karman suggests authorities wanted to deny the pro-Morsi camp the publicity she would have generated. Morsi supporters strongly condemned Karman's barring, claiming it was evidence of the "resurrection" of the police state under autocrat Hosni Mubarak, toppled in a 2011 popular uprising.