Cairo (CNN) -- Several rights groups, including three U.S.-based entities, were raided in Cairo and other Egyptian locations on Thursday in what one source called a push by police to "show some muscle."
Police conducted 17 raids of nongovernmental organizations, targeting at least 10 groups across the country, Egypt's general prosecutor's office said. The targeted groups included U.S.-based Freedom House, the National Democratic Institute (NDI) and the International Republican Institute (IRI).
The actions were part of an investigation into allegations that groups may have received illegal foreign funding and have been operating without licenses from the Foreign Ministry and local ministries, according to Adel Saeed, spokesman for the general prosecutor's office.
But the leaders of the U.S.-based organizations and the U.S. State Department condemned the raids and called on Egyptian authorities to allow the groups to resume their work.
"This action is inconsistent with the bilateral cooperation we have had over many years," State Department spokeswoman Victoria Nuland said Thursday. Washington has called on Egyptian authorities "to immediately end the harassment of NGOs (and) NGO staff, return all property and resolve this issue immediately."
And David Kramer, the president of Freedom House, called the crackdown "an escalation of repression unheard of even during the Mubarak regime."
"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," Kramer said in a statement. "It is the clearest indication yet that the Supreme Council of the Armed Forces, the military chiefs now ruling Egypt, has no intention of permitting the establishment of genuine democracy and is attempting to scapegoat civil society for its own abysmal failure to manage Egypt's transition effectively."
Saeed, the prosecutor's office spokesman, said that some of the NGO offices were shut down "and some computers and documents have been confiscated. A report will be prepared and sent to the judicial authorities for further investigations."
He said police secured premises while prosecutors conducted the searches and seizures.
Freedom House said at least two Egypt-based organizations -- the Arab Center for Independence of Justice and Legal Professions, and the Budgetary and Human Rights Observatory -- also were raided. Freedom House urged the Obama administration to "scrutinize the $1.3 billion that the United States annually provides the Egyptian military to fund arms purchases and training."
"In the current fiscal environment, the United States must not subsidize authoritarianism in Egypt while the Egyptian government is preventing NGOs from implementing democracy and human rights projects subsidized by the U.S. taxpayer," said Charles Dunne, Freedom House's director of Middle East and North Africa programs.
The other two U.S.-based groups, NDI and IRI, promote democratic institutions across the globe and had delegations observing Egypt's parliamentary elections. Both receive some funding from U.S. government agencies and are non-partisan, though affiliated loosely with the major American political parties.
The current chairman of the IRI's board of directors, Sen. John McCain of Arizona, called the Egyptian crackdown "unjustified" and "reminiscent of the practices of the Mubarak regime."
"I call on Egypt's military leaders to allow non-governmental organizations in Egypt to operate freely and without restrictions, to safeguard the universal human rights of all Egyptians and to enable the people of Egypt to realize their aspirations for a full transition to a civilian, democratic government through a fair, inclusive and transparent process," McCain said in a written statement.
And Julie Hughes, the NDI country director for Egypt, said security forces "simultaneously raided" offices in Cairo, Alexandria, and Assiut. She called the raids "surprising."
"They took laptops, papers, electronic devices, financial records, video equipment we used to do video training for participants -- things we use for media training," Hughes said. "We don't really know what this is about. There was no warrant presented, no explanation given, and no names of the individuals who were seizing the property."
A person associated with NDI told CNN that the officers who raided the Cairo offices "took everything, every shred of paper, computers, personal laptops." The source was not authorized to speak on the record and so spoke to CNN on background.
Police targeted an officially accredited election observation team, the source said, and appeared to be an attempt by the Egyptian police to "show some muscle" -- to allege that NDI is supposedly funded by a foreign government.
Both organizations have operated in Egypt since 2005.
Egypt has been ruled by the military since the ouster of former President Hosni Mubarak in February. It has begun parliamentary elections, with Islamist parties -- particularly the Muslim Brotherhood's Freedom and Justice Party and the Al Noor Salafi Movement -- prevailing in the elections so far.
Naser Amin, manager and founder of the Arab judicial center, said security forces seized "a lot of material" as they stormed the office in search of computers and documents.
"They showed us a judicial order for a search operation and closure of the center without even accusing us officially," he said. "I don't understand how they decided we were getting foreign funding without questioning any of us."
CNN's Mohamed Fadel Fahmy and Mohammed Jamjoom in Cairo, Jill Dougherty and Pam Benson in Washington, and Joe Sterling in Atlanta contributed to this report.