WASHINGTON >> The White House violated a court order on deportations to third countries with a flight linked to the chaotic African nation of South Sudan, a federal judge said Wednesday, hours after the Trump administration said it had expelled eight immigrants convicted of violent crimes but refused to reveal where they would end up.

In an emergency hearing called to address reports that immigrants had been sent to South Sudan, Judge Brian E. Murphy in Boston said the eight migrants aboard the plane were not given a meaningful opportunity to object that the deportation could put them in danger.

“The department actions in this case are unquestionably in violation of this court’s order,” Murphy said Wednesday, arguing that the deportees didn’t have “meaningful opportunity” to object to being sent to South Sudan. The group was flown out of the United States just hours after getting notice, leaving them no chance to contact lawyers who could object in court.

Government attorneys argued that the men had a history with the immigration system, giving them prior opportunities to express a fear of being deported to a country outside their homeland.

They also pointed out that the judge had not specified the exact time needed between notice and deportation, leaving room for misunderstanding.

The government calls the deported people ‘true national security threats’

The migrants’ home countries — Cuba, Laos, Mexico, Myanmar, Vietnam and South Sudan — would not take them back, according to Todd Lyons, the acting director of Immigration and Customs Enforcement, who spoke to reporters in Washington. He later said the migrants either came from countries that often do not take back all their deported citizens or had other situations that meant they could not be sent home.

“These represent the true national security threats,” Lyons said at a news conference.