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LOS ANGELES — Civil rights advocates have filed a class-action lawsuit against the U.S. government to challenge the immigration detention of Cambodian nationals, many of whom came to the U.S. as refugees.

The advocates said that over the past several weeks, Immigration and Customs Enforcement (ICE) has detained more than 100 Cambodian nationals with orders of removal.

“What we’ve seen here is that ICE has redetained class members without complying with their obligations under the law and our Constitution,” Christopher Lapinig, a legal fellow at Asian Americans Advancing Justice-Los Angeles (Advancing Justice-LA), said Wednesday. “They have not given notice as to the reasons why the class members have been redetained, and they did not give any individualized consideration as to whether or not each individual who is being redetained poses any risk to the community in terms of safety or poses a risk in terms of flight.”

Nonprofits Advancing Justice-LA and Asian Americans Advancing Justice-Asian Law Caucus filed the lawsuit Oct. 27 with law firm Sidley Austin LLP.

ICE declined to comment on the pending litigation.

More than 1,900 Cambodian nationals in the U.S. are subject to a final order of removal, about 1,400 of whom have criminal convictions and 500 of whom have no lawful status to remain in the country, ICE told NBC News in September.

Lian Cheun — executive director of Khmer Girls in Action, a Southern California nonprofit that works with young Southeast Asian women — said Wednesday that the majority of Cambodians who are deported are men, many of whom serve as breadwinners in their families.

Plaintiffs fled Cambodia as refugees in the 1970s to escape the Khmer Rouge, according to the lawsuit.

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“Many folks are still working on the process of healing from our immigration history and refugee history background, but also the compounded trauma of dealing with poverty, racism and a lot of different structural issues in our community,” Cheun said.

Christopher Lapinig, a legal fellow at Asian Americans Advancing Justice - Los Angeles, speaks during a press conference announcing a lawsuit over ICE detentions of Cambodian Americans. Agnes Constante / NBC News

Many of the individuals targeted in the recent roundups reside in California, the lawsuit states, including lead plaintiffs Nad Kim Chhoeun and Mony Neth, who both arrived in the United States as children in the 1980s.

Both were detained on Oct. 20 and were not provided with any reason for their detention, the lawsuit alleges.

Posda Tuot, Chhoeun’s cousin, said that he took Chhoeun to a scheduled immigration check-in last month at an ICE facility in Southern California, but Chhoeun never made it back out.

“The day I brought him in, it was just heartbreaking just not seeing him walk out,” Tuot said.

Tuot said that his cousin was a hardworking and positive person and went in despite being aware of ongoing detentions at the time.

“If he was a flight risk, he wouldn’t have went in,” he said.

In 1995, Neth was convicted of unlawful possession of a weapon, participating in a criminal street gang, and receipt of stolen property. Chhoeun pleaded guilty on charges of simple assault and unlawful possession of a firearm in 1999.

“He did his crime, came out changed, but yet America deports him for something he did early in his life,” Tuot said.

Laboni Hoq, litigation director at Advancing Justice-LA, said the hope is for the lawsuit to result in a legal ruling that stops ICE from conducting raids. According to the suit, ICE officers have raided homes and workplaces. Some individuals were also detained during regularly-scheduled check-ins and others had been asked to report to ICE early and were detained when they arrived, the lawsuit stated.

“This community of people is entitled to know why they’re being detained,” Hoq said. “They’re entitled to establish immediately that they should not be detained because they don’t pose a danger or a flight risk and that ICE can’t detain them because there’s no reasonable foreseeability that they’re going to be repatriated back to Cambodia because there is no information that Cambodia will actually take them back.”

The lawsuit comes about a month-and-a-half after the Cambodian Ministry of Foreign Affairs and International Cooperation announced that it planned to interview 26 nationals facing deportation in response to visa sanctions imposed on certain high-ranking officials by the U.S.

In a statement dated Sept. 14, the ministry said it had asked to renegotiate Cambodia's 2002 repatriation agreement with the U.S. in October 2016 after "fierce protests from Cambodian-American communities, Cambodians living in the country and some United States congressmen."

"The proposal sought to provide opportunity for both parties to discuss and amend the above-mentioned memorandum in line with humanitarian, compassionate and human rights aspects ... with a view to avoiding family separation and encouraging full integration to society," the statement said.

On average, Cambodia has accepted 35 individuals for repatriation each year, the lawsuit states.

Between October 2016 and Aug. 5, 28 Cambodian nationals were deported, ICE has said.

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