An officer with the US Immigration and Customs Enforcement's (ICE) Fugitive Operations team search for a Mexican national at a home in Hawthorne, California, U.S., March 1, 2020: REUTERS/Lucy Nicholson

Two staff members at facilities for immigrant detainees have tested positive for the coronavirus, raising concerns of outbreaks in detention centres across the country.

It comes just days after immigration advocates had warned that the notoriously overcrowded detention facilities could become hotspots for the virus.

Some 38,000 immigrants are currently being held in more than 200 facilities in the US, in addition to around 3,600 immigrant children who crossed into the United States alone or who were separated from adults at the US-Mexico border.

One of the infected staff members was an administrator at a US Immigration and Customs Enforcement (ICE) detention centre in New Jersey, a spokesperson for the agency said. They added that the role typically does not involve direct contact with detainees.

The other person worked at a facility housing children in New York.

Earlier this week, the American Civil Liberties Union sued ICE to release illegal immigrants who are “particularly vulnerable” to the coronavirus.

“Immigrant detention centers are institutions that uniquely heighten the danger of disease transmission. In normal circumstances, ICE has proven time and again that it is unable to protect the health and safety of detained people,” Eunice Cho, senior staff attorney at the ACLU’s National Prison Project, said in a statement.

ICE had recently come under fire for launching a crackdown in several sanctuary cities across the country in the midst of the coronavirus outbreak. Democrats in both houses had warned that the crackdown would deter undocumented immigrants from seeking medical help, and may contribute to the spread of the virus.

Then on Wednesday, ICE announced it "temporarily adjust its enforcement posture" to focus on "public safety risks" and people "subject to mandatory detention on criminal grounds."