Family members of Venezuelan migrants who suspect their loved ones were sent to El Salvador as part of a rapid U.S. deportation operation over the weekend are struggling to get more information as a legal battle plays out.

Human rights advocates warn that the deportees legal rights were violated as they were transferred to the CECOT, a mega-prison established by El Salvador’s President Nayib Bukele for his crackdown on gangs in the country. The facility, according to the Associated Press, can hold up to 40,000 inmates; up to 70 people are housed in a single cell.

Venezuela's National Assembly President Jorge Rodriguez said on Monday that Venezuelans deported over the weekend to El Salvador by the United States have been denied due process. The lawmaker added during a press conference that the people deported under a Trump administration claim that they belong to the Tren de Aragua gang are not known to have committed any crimes in the United States or El Salvador,