CAIRO -- The Egyptian authorities on Thursday warned tens of thousands of supporters of former President Mohamed Morsi to abandon their sit-ins, in what was seen as the first step toward the use of force one day after the military-backed government ordered that the protests must end.
Speaking on state television, an Interior Ministry spokesman appealed to the protesters to "give priority to the interest of the homeland, to comply with the public interest and to quickly leave and evacuate." The ministry promised "safe exit and complete protection" to all who complied, said the spokesman, Hany Abdul-Laatef.
Responding to the Interior Ministry warning, an alliance of Mr. Morsi's supporters said that the sit-ins were peaceful and would continue, and that the alliance "places full responsibility on the coup leaders for any acts of violence or killings."
For weeks, Mr. Morsi's supporters have been occupying two squares in Cairo -- Rabaa al-Adaweya in Nasr City and Nahdet Misr near Cairo University -- to protest his ouster on July 3. They have vowed to remain until the former president is released from military detention and reinstated.
The sit-ins have become flash points for the bloodiest confrontations since Mr. Morsi's ouster, including the killings of more than 140 of his Islamist supporters by Egyptian security services. And as they grow more permanent, with stores and barbers and even their own television station, the encampments have become potent symbols of Egypt's impasse.
On Wednesday, Egypt's interim cabinet said the sit-ins were disruptive and represented "a threat to the Egyptian national security and an unacceptable terrorizing of citizens" and ordered the security forces to end them.
Rights groups denounced the decree as a new provocation to violence. "Given the Egyptian security forces' record of policing demonstrations with the routine use of excessive and unwarranted lethal force, this latest announcement gives a seal of approval to further abuse," Amnesty International said in a statement on its Web site, calling the decree a "recipe for further bloodshed."
The authorities have portrayed the sit-ins as hotbeds of "terrorism," a term they use loosely to describe their opponents. Officials have accused the Islamists of storing weapons and perpetrating abuses, including the fatal torture of at least 14 people, in the two squares.
The cabinet's decree represented an effort to bolster the legal case for dispersing the sit-ins by force. It came after the interim prime minister met with Egypt's military commander, Gen. Abdul-Fattah el-Sisi, and the interior minister. On television, the Minister of Media, Dorreya Sharaf el-Din, said the decree was necessary because of "the huge mandate given to the state by the people in dealing with the terrorism and the violence that threaten the dissolution of the state and the collapse of the homeland, and in order to protect the national security and higher interest of the country, and the social peace and the safety of citizens."
She said the Interior Ministry had been instructed "to take all the necessary measures in that regard within the framework of the provisions of the Constitution and the law."
The Obama administration, which has been engaged in a delicate balancing act over how to deal with the Egypt crisis, expressed concern. Asked about the new decree at a daily State Department briefing in Washington, the deputy spokeswoman, Marie Harf, said: "We have continued to urge the interim government officials and security forces to respect the right of peaceful assembly. That obviously includes sit-ins."
On Tuesday, two Republican senators, Lindsey Graham of South Carolina and John McCain of Arizona, frequent critics of President Obama, said he had asked them to visit Egypt next week to help persuade the interim leaders to move forward with new elections and an inclusive government. The senators said they would convey a bipartisan message from the United States, which has regarded Egypt as a crucial ally in the region for decades and provides $1.5 billion in annual aid.
The decree on Wednesday aimed at ending the sit-ins came shortly after the interim authorities announced they had referred Brotherhood leaders to a criminal court on charges of incitement to violence. They included the movement's spiritual leader, Mohamed Badie, and Khairat el-Shater, its onetime candidate for president. That was seen as a further expansion of the crackdown on the Brotherhood that has included arrests, closing of television stations and an effort to purge state institutions of the movement's members.
The military has detained Mr. Morsi and kept his whereabouts secret. He has not been allowed to communicate with his family or a lawyer. This week the European Union's top foreign policy official, Catherine Ashton, visited him and said he was in good health. On Wednesday, an African Union delegation said it had also visited Mr. Morsi, according to Ahram Online, an English-language news site.
During the visit Tuesday night, Mr. Morsi told the African delegation that he was powerless to end the crisis, the former president of Botswana, Festus G. Mogae, told the news site.
"Morsi told us that he cannot do anything in the current situation, as he does not have contact with the media or his followers," Mr. Mogae said.
This article originally appeared in The New York Times.