The excavators found 27 other presumed graves near the grounds of a notorious reform school in Florida.
Workers hired to clean up a fuel storage site have discovered new "anomalies" buried near the Dozier School for Boys public school, officials said.
The school has become infamous for abuse and alleged killings of children during its 111-year history.
It was one of the largest institutions for young offenders in the United States, which finally closed in 2011.
If confirmed, the latest findings would bring to 82 the total number of burials known on campus – although researchers believe that more than 100 children could have died at the Dozier School.
- An abuse investigation in the United States exhumes the boys' bodies
- Who were the children buried at Dozier School?
Contractor New South Associates was preparing to clean up pollution in Marianna, Fla., Using a ground penetrating radar in March when workers discovered what could be more burial sites near the school.
Their report, obtained by the Florida newspaper, the Tampa Bay Times, indicates that possible graves do not follow any pattern.
"This chance could be expected in a clandestine or informal cemetery," says the report.
New South recommended treating the area as a cemetery until further investigation can be conducted.
Florida Governor Ron DeSantis has asked state authorities to "define a way forward" to understand the results.
A group of former students known as White House Boys made the public aware in the 2000s of allegations of abuse against the institution.
"We have been trying for a long time to tell the state of Florida that there are more bodies out there," said Middleton's Bryant at the Tampa Bay Times.
Terry Burns, another Dozier School alumna, told Action News that if he analyzed the entire campus, "I guarantee they will find 200 to 300 other dead boys buried under their roof."