In the latest chapter of the child labor abuse across the U.S., federal officials on Wednesday alleged a janitorial service hired as many as nine teenagers to clean a pork slaughterhouse in Sioux City, Iowa.

Fayette Janitorial, based in Tennessee, employed "oppressive labor," according to accusations from U.S. Labor Department officials, who asked a federal judge in northern Iowa to issue an injunction to block the company from violating federal labor law.

In total, the complaint said 24 children, one as young as 13 years old, are said to have worked for Fayette cleaning the kill floor and meat bandsaws at the Perdue Farms plant in Accomac, Va., and the Seaboard Triumph Foods plant in Sioux City. The minors worked overnight on job sites deemed "hazardous" under federal law.

In Virginia, investigators say a 14-year-old suffered severe injury.

In a response on Thursday, Fayette Janitorial said they maintain a "zero-tolerance" policy for hiring minors and has been "fully cooperating" with the Labor Department's investigation.

In a statement provided to the Star Tribune, a Perdue spokeswoman said underage labor "has no place in our business or our industry." The spokeswoman added that Perdue terminated its contract with Fayette before the court filing.

Seaboard Triumph said the allegations against its outside vendor found them "disturbed." It, too, has ended "all contracts with Fayette."

The allegations are the latest in a 16-month crackdown on child labor across the nation. Last week, labor officials in Madelia, Minn., called upon Mankato-based Tony Downs Foods to establish a welfare fund for youth, following allegations by state labor authorities that the company illegally employed minors — charges the company disputes.

In fall 2022, federal Labor Department officials also uncovered teenagers cleaning at a JBS pork plant in Worthington, close to the Iowa border. In fiscal year 2023, the Labor Department tracked labor violations in nearly 1,000 cases, said authorities.