Vietnamese immigrants in the United States have filed a class action lawsuit against U.S. Immigration and Customs Enforcement (ICE) for putting them in detention facilities as they await deportation on an indefinite basis. They were rounded up and put there despite Vietnam’s lack of response on whether it will accept to take them back or not.

Lawyers of the detainees said on Wednesday that Vietnam only agreed to repatriate deportees that had come to the U.S. after the two countries renewed its diplomatic relations in 1995, Associated Press reported.

According to the attorneys, the Trump administration began arresting deportees who came to the U.S. before the diplomatic relations renewal so that it could broaden the two nations’ repatriation agreement.

“They are just using this as an excuse to round up people indiscriminately in the hope they can then convince Vietnam to take them back,” litigation director for Asian Americans Advancing Justice in Los Angeles, Laboni Hoq, said in a statement.

The lawsuit cites Hoang Trinh, who came to the U.S. when he was four as part of a large Catholic family that fled Vietnam, as well as three other petitioners that are among approximately 40 refugees that are currently being housed in detention facilities as they await deportation, The OC Register reported.

It was also reported that some of them have already been detained for more than 90 days, while others have been in the facilities for as long as 11 months. Attorneys said that this can be considered illegal as the U.S. has no rights to hold these people indefinitely unless their country of origin expressed that they would them back.

A 2008 agreement that sets the conditions stating that only those who have moved to the United States on or after July 12, 1995 are subjected to the repatriation agreement – the Vietnamese government considers request on a case-by-case basis. However, those who left Vietnam for the U.S. before the said date may not be deported back to their country of origin, the report continued.

“Today, the American government – the one that my mom equates with freedom and justice – is illegally and indefinitely incarcerating Vietnamese refugees who came to the United States before July 12, 1995 and who therefore cannot be removed under a longstanding agreement between Vietnam and the United States,” litigation director with the Asian Americans Advancing Justice, Atlanta affiliate, Phi Nguyen, said. Nguyen’s family are Vietnamese refugees, but none of them are being represented in the lawsuit.

It is still currently unknown how many of the 1.3 million Vietnamese immigrants currently living in the U.S. came to the country before 1995. Reports believe that those who moved to the U.S. before the renewal of diplomatic relations are the ones who fled Vietnam after the fall of Saigon to communist forces in 1975.

The Department of Homeland Security’s Immigration and Customs Enforcement (ICE) agency began arresting Vietnamese immigrants in Georgia, Pennsylvania, Texas, Colorado and California last year. Some in the community are now in fear that they, too, could get arrested and detained for deportation even if they’ve been living in the country for decades.