CAIRO — Egyptian authorities on Thursday raided the offices of 17 domestic and international human rights and pro-democracy organizations, including several that receive U.S. government funding, in a sharp intensification of the military's crackdown that recalled the tactics of the country's ousted authoritarian president, Hosni Mubarak.

The raids in Cairo and other cities appeared to be an effort by the ruling military to intimidate nongovernmental organizations that it accuses of promoting a "foreign agenda" and supporting protests against its rule.

Dozens of police officers, military personnel and judicial officials held and interrogated staff members for several hours, confiscated computers and documents, and closed at least five of the offices, the agencies said. They said the searches were conducted without warrants.

"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 last February. The third and final round of those polls is scheduled to begin next week.

Both groups said in statements that their work focused on promoting democratic participation and that they didn't 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 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 of the discussions.