Screenshots reportedly from a secret Facebook group for current and former Border Patrol agents, with thousands of members, show posts that joked about the deaths of migrants and discussed throwing burritos at Latino members of Congress visiting detention facilities in Texas on Monday.

The three-year-old group, which has roughly 9,500 members, shared derogatory and sexist comments about lawmakers, including Reps. Alexandria Ocasio-Cortez, D-N.Y., and Veronica Escobar, D-Texas, ProPublica reported Monday. The group is reportedly called “I’m 10-15." The agency's code for "aliens in custody" is 10-15.

Border Patrol chief Carla Provost condemned the posts in a statement Monday.

“These posts are completely inappropriate and contrary to the honor and integrity I see — and expect — from our agents day in and day out,” Provost said. “Any employees found to have violated our standards of conduct will be held accountable.”

CBP said it informed the Department of Homeland Security inspector general of the "disturbing social media activity" and launched an investigation into the Facebook group.

ProPublica said it had received images of several recent discussions in the Facebook group and "was able to link the participants in those online conversations to apparently legitimate Facebook profiles belonging to Border Patrol agents, including a supervisor based in El Paso, Texas, and an agent in Eagle Pass, Texas."

The investigative journalism organization said it was unable to reach the group members who made the postings.

NBC News has not independently verified this Facebook group and has not seen the posts.

One member, apparently a patrol supervisor, wrote, “F--- the hoes,” referring to Monday's CBP visits by Ocasio-Cortez and Escobar. “There should be no photo ops for these scum buckets,” wrote another member.

Ocasio-Cortez, who ProPublica said was a target of most of the disturbing posts, some of which were sexually explicit, responded to the report in a series of tweets Monday and questioned the agency's ability "to care for refugees humanely."

"They’re threatening violence on members of Congress," she wrote. "How do you think they’re treating caged children+families?"

After touring a facility in El Paso on Monday, she tweeted, "I see why CBP officers were being so physically & sexually threatening towards me. Officers were keeping women in cells w/ no water & had told them to drink out of the toilets."

CBP has been accused of mistreating children and adults in its custody. Ocasio-Cortez has compared the Trump administration’s border detention facilities to “concentration camps,” eliciting criticism that she was minimizing the Holocaust.

In one exchange in the 10-15 Facebook group, members responded crassly or with indifference to a news story about a 16-year-old Guatemalan migrant who died in May while in custody at a Border Patrol station in Weslaco, Texas, according to ProPublica. One member responded with a GIF of Elmo with the quote, “Oh well.” Another posted an image and the words “If he dies, he dies.”

The National Border Patrol Council, the official union of Border Patrol employees, said its representatives have “spoken with agents in the workplace and at membership meetings about the need to be professional while on social media and that posting material that is inappropriate and unacceptable does great harm to the reputation of the Border Patrol.”

The union said that content found in the "I'm 10-15" Facebook group is not representative of its employees and "does a great disservice to all Border Patrol agents, the overwhelming majority of whom perform their duties honorably."