In a statewide conference call this week, Minnesota's top education official scolded more than 70 superintendents about their failure to address teacher licensing violations.

Superintendents "need to understand that this is very serious, and we're going to hold them accountable," Education Commissioner Brenda Cassellius told the Star Tribune. "There's a different level of awareness and scrutiny. I want these taken care of."

To prod districts into complying with the rules, the department will threaten to withhold state funds from districts that fail to correct licensing violations in a timely manner, Cassellius said. In recent years, such steps were taken only twice.

The Education Department may also post the number of improperly licensed teachers on each school's online report card, she said.

Cassellius' rebuke comes less than two weeks after a Star Tribune investigation revealed how state officials have routinely ignored teacher licensing violations in recent years.

Since 2005, more than 900 teachers violated rules aimed at making sure children get proper educations, including 62 who worked with no license at all, according to the newspaper's analysis of state education records. The violations, which mostly involved instructors teaching the wrong subject or grade level, touched as many as 57,000 students in about 300 public school districts and charter schools statewide, records show.

While the number of violations has dropped in recent years, repeat offenders remain a problem, Cassellius told about 70 school leaders in a conference call on Wednesday.

After checking records this spring, state officials discovered that more than a third of 198 violations uncovered last fall still had not been corrected, Cassellius said.

While the Education Department controls state funding for school districts, licensing is directly overseen by the state Board of Teaching, which regulates more than 50,000 working teachers. Typically, fewer than 1 percent of those teachers violate the rules in any given year.

With a $618,000 annual budget and three full- and four part-time employees, the Board of Teaching does not have the time or money to track down all violators, executive director Karen Balmer said.

Balmer said it would probably cost millions of dollars to fully enforce licensing standards each year, but she said it would still be difficult to remove teachers who flout the rules. She cited a 2000 case where an administrative law judge recommended neither removing nor suspending a Moorhead music teacher even though the instructor worked with an expired license for five years.

Cassellius questions whether enforcement efforts require more state funding.

"It's about training and compliance and holding people accountable," Cassellius said.

Gov. Mark Dayton, who appoints the Board of Teaching, can replace more than half of the 11-member panel over the next year. Cassellius said the governor told her he is not considering a major overhaul of the board's operations.

Cassellius urged superintendents to make sure their principals receive whatever training they need to avoid licensing problems when they make classroom assignments.

In a continuing case that will cost the Minneapolis Public School District at least $92,000, investigators recently determined that at least two unlicensed instructors worked at Minneapolis' Broadway High School for at least six years, from 2004 to late 2010. Graduation for more than a dozen students at the school, which helps pregnant and parenting teenagers, will be delayed this spring because of the problem.

Last week, Minneapolis school board members voted to fire Mary Pat Sigurdson, who oversees the high school as district coordinator of the Teenage Pregnancy and Parenting Program. At least one other employee remains on administrative leave. The district has dismissed the unlicensed instructors.

Cassellius played an unwitting role in the breakdown at Broadway High. When she worked as an associate superintendent in Minneapolis from 2007 to 2010, overseeing Sigurdson and Broadway High were among her duties one year.

"It was never reported to me," she said.

Corey Mitchell • 612-673-4491