Forty-three employees of NGOs in Egypt, including 19 Americans, have been charged with using foreign funds to incite violence in the country.

Sam LaHood, the son of U.S. Transportation Secretary Ray LaHood, reportedly is one of the American NGO employees whose case has been referred to a criminal trial in Egypt. LaHood is among the Americans who have been barred from leaving the country since Jan. 21.

“We are deeply concerned by these reports and are seeking clarification from the government of Egypt,” U.S. State Department spokesman Mark Toner said Sunday in response to reports of the indictments.

The Obama administration and senior congressional leaders have warned Egypt that the investigation and trials could jeopardize some $1.55 billion in American aid to Egypt, the majority of it military assistance, The New York Times reported.

Egyptian government forces on Dec. 29 raided the offices of 17 foreign NGOs, including U.S. groups that monitored recent parliamentary elections there, according to Politico. The offices were shut down and the employees questioned.

The forces reportedly seized computers, documents and cash; the groups are accused of using foreign funds to support unrest in Egypt.

U.S. groups that were raided include the International Republican Institute and National Democratic Institute. Both had been invited to monitor the recent elections, but lacked a license to operate from the Egyptian government, which had been a requirement under the Mubarak regime.