"The raids today represent an escalation of repression unheard of even during the Mubarak regime," said David J. Kramer, the president of Freedom House, a U.S.-based pro-democracy group whose offices in Cairo were among those raided.
"These actions come in the context of an intensive campaign by the Egyptian government to dismantle civil society through a politically motivated legal campaign aimed at preventing 'illegal foreign funding' of civil society operations in Egypt."
Egypt's state-owned Middle East News Agency reported that the raids "took place as a part of a broad and ongoing investigation into the operations of several NGOs accused of illegally receiving foreign funds."
Among the offices raided and closed were those of the International Republican Institute and the National Democratic Institute, two U.S.-based groups that receive American government funding and had been assisting Egyptian political parties in their campaigns for the recent parliamentary elections, the first since Mubarak resigned in February. The third and final round of those polls is to begin next week.
Both groups said in statements that their work focused on promoting democratic participation and that they did not provide financial or material support to individual parties, candidates, or civic groups.
"Cracking down on organizations whose sole purpose is to support the democratic process during Egypt's historic transition sends a disturbing signal," said National Democratic Institute president Kenneth Wollack.
In Washington, State Department spokeswoman Victoria Nuland said the United States was "deeply concerned" about the raids, called for the immediate return of computers and other seized property, and demanded that Egyptian authorities "immediately end the harassment of NGO staff."
"We don't think the action is justified, and we want to see the harassment end," Nuland said.
"We believe that these NGOs are there to support the democratic process. We have been very open and transparent with Egyptian authorities at all levels, particularly about the operating procedures and policies of NDI, IRI, and other international . . . NGOs that we support. So we are very concerned, because this is not appropriate in the current environment."
Nuland said that the U.S. ambassador to Egypt, Anne Patterson, had been in touch with Egyptian Prime Minister Kamal el-Ganzouri and that a senior State Department official had spoken with Egypt's envoy to Washington, Sameh Shoukry. She said the U.S. officials had made "strong representations" to their Egyptian counterparts, but she declined to reveal details.
Egyptian groups described the raids as the latest in a string of attacks on their work by the Supreme Council of the Armed Forces, which has ruled since Mubarak resigned and is supposed to be paving the way to a new democratic government. All the groups that were targeted have spoken out against military trials of civilians and acts of torture against protesters, such as forced virginity tests for women.
"Today's unjustified acts represent a long list of legal violations," said Hafez Abu Seada, the director of the Egyptian Organization for Human Rights, which held a news conference condemning the raids.
Abu Seada noted that the security and judicial personnel conducting the raids did not document the items they seized, suggesting - in a nod to security forces' Mubarak-era tactics - that "they could fabricate any evidence and announce finding it among what they confiscated."
A statement that 25 Egyptian and international agencies signed after the raids said: "This shameful violation that we never witnessed even under the Mubarak regime is an attempt by the ruling military to cover for its failure in administrating the country during the transitional period and fulfilling the demands of the revolution" that toppled Mubarak.
Egyptian law makes it extremely difficult for most human-rights groups to obtain licenses, leaving many to operate unofficially.