WASHINGTON (AP) — More than 70 percent of students involved in school-related arrests or cases referred to law enforcement were Hispanic or African-American, according to an Education Department report that raises questions about whether students of all races are disciplined evenhandedly in America’s schools.

Black students are more than three times as likely as their white peers to be suspended or expelled, according to an early snapshot of the report released to reporters. The findings come from a national collection of civil rights data from 2009-10 of more than 72,000 schools serving 85 percent of the nation.

The Education Department said it would release more details Tuesday.

“The sad fact is that minority students across America face much harsher discipline than non-minorities, even within the same school,” Education Secretary Arne Duncan told reporters.

Duncan said some school officials might not have been aware of inconsistencies in how they handle discipline, and he hoped the report would be an eye-opener.

According to the report, 42 percent of the referrals to law enforcement involve black students and 29 percent involved Hispanics, while 35 percent of students involved in school-related arrests were black and 37 percent were Hispanic.

Black students made up 18 percent of the students in the sample, but they were 35 percent of students suspended once and 39 percent of students expelled, the report said.

Copyright 2012 The Associated Press.