U.S. Representative Raul Grijalva introduces U.S. Sen. Bernie Sanders during a Future to Believe In Tucson Rally in 2016. 

WASHINGTON — Democratic members of Congress are demanding the Department of Homeland Security investigate claims of sexual harassment at immigration facilities.

A letter to Homeland Security Secretary Kirstjen Nielsen and acting Immigrations and Customs Enforcement acting Director Thomas Homan was signed by 73 Democratic members of Congress, azcentral.com reports.

The letter said the department failed to investigate reports of sexual abuse.

The Community Initiatives for Visiting Immigrants in Confinement said that of the 1,016 incidents of sexual abuse reported from 2014 to 2016, only 24 were investigated.

“DHS and its partner agencies must be held accountable for rampant complaints of sexual assault, abuse and harassment within their immigrant detention facilities,” said Rep. Raul Grijalva of Arizona.

A statement from ICE said there was “zero tolerance” for sexual abuse.

“Accusations of alleged unlawful conduct are investigated thoroughly and appropriate action is taken to ensure the safety and security of those involved and others in ICE custody,” the statement said.

Among the instances cited in the letter were a case where an immigrant was interviewed about a complaint about rape more than two years after filing it; an immigrant woman being sexually assaulted after being transferred; a child having signs of sexually transmitted diseases, but having allegations called unfounded; and a transgender woman being forced to be strip searched by an officer and slowly remove each article of clothing.