Immigration lawyers told the court that U.S. President Donald Trump's administration has deported two Asian men to South Sudan.

A flight carrying more than a dozen people, including Myanmar and Vietnamese citizens, landed in South Sudan on Tuesday, lawyers said in a filing with a federal judge in Boston.

Previous court orders prohibited the U.S. government from deporting immigrants to third countries without giving "meaningful opportunities" to challenge such dismissals.

The BBC has contacted the Department of Homeland Security for comment. South Sudan is one of the poorest countries in the world and has been plagued by conflict and political unrest in recent years.

Attorneys for the National Immigration Litigation Alliance asked a federal judge Tuesday about an emergency order to prevent deportation.

Judge Brian Murphy issued a ruling on April 18 that required illegal immigrants to have the opportunity to challenge evacuation of countries outside their homelands.

In reports that some immigrants will be sent to Libya, a Biden-appointed judge Murphy said any such move would violate his ruling.

Lawyers for the Burmese man said in a court application Tuesday that their client spoke limited English and refused to sign a dismissal notice signed by Texas Immigration Detention Center officials.

The court applied to say that an attorney sent an email to the center after noticing that the client no longer appeared in the U.S. immigration and customs law enforcement officer detainee locator, the court applied. She was told he had evacuated from the United States.

When she asked which country the relocated client was in, the email replied: "South Sudan."

The lawyer said another client, a Vietnamese man, “seemed to suffer the same fate”, “with a man from Myanmar” and “is or is flying the same.”

The spouse of a Vietnamese man sent an email to a lawyer, Reuters reported, saying that about 10 people believed to have been deported include Laos, Thailand, Pakistan and Mexican nationals.

"Please help!" said the spouse in an email. “They can’t allow it.”

"Do not travel to South Sudan due to crime, kidnapping and armed conflicts," the U.S. government travel advisor said.

Africa's youngest country, it suffered a bloody civil war shortly after its independence in 2011.