A one-day sweep in which over 150 high school students were suspended for dress code violations is bringing new criticism to a Connecticut district of predominantly Hispanic and black students that was already under scrutiny for having low numbers of minority teachers.

The students, summoned dozens at a time, were called out of class by loudspeakers and ordered to sit out the next school day for wearing hoodies, forbidden colors or other violations. Among those caught up in the sweep at Wilby High School two weeks ago were first-time offenders like Allyanna Jones, a 16-year-old honors student.

"I said, 'I'd rather be cold than suspended,'" Allyanna said of her offer to remove a sweat shirt. "They said, 'It's only a day. You'll get over it.'"

The district office later wiped the suspensions from students' records, noting schools are supposed to issue lesser punishments for first violations. But activists say they reflect deeper problems with the climate at the high school, where half of all students received at least one suspension last year.

"This is the purest example of promoting discipline over academic performance," said Robert Goodrich, a co-founder of Radical Advocates for Cross-Cultural Education in Waterbury. He likened it to "broken windows" policing, which aims to keep peace by cracking down on minor offenses.

The Wilby High dress code calls for boys to wear black or green shirts, with their pants or shorts worn or belted at the waist. Skirts, dresses, pants and shorts for girls are required to be navy blue, black, gray or khaki. Hats, caps and hoodies are forbidden.

Nationwide, school districts have been revising policies to reduce suspensions and expulsions. Federal government studies have shown blacks and Hispanics are far more likely to face such harsh punishments, and as a result of more police involvement with schools, instances more frequently lead to arrests in what is known as the "school-to-prison pipeline."

Darren Schwartz, the Waterbury district's chief academic officer, says it has been making progress in curbing suspensions. By working to understand the root causes of behavioral problems and intervening when possible, he said, the district has achieved a 12 percent reduction in suspensions over the past five years. Last year, the district of 18,862 students had 12,810 suspensions.

At the urging of the NAACP, the Connecticut Commission on Human Rights and Opportunities has been looking into faculty hiring practices in Waterbury. The commission has been working with the district on developing best practices, and the findings of its yearlong investigation are expected within a month.

At Wilby High, 84 percent of the students are Hispanic or black, while 83 percent of educators are white. Some critics say the discipline rates reflect a lack of cultural sensitivity among the faculty.

"The NAACP has been fighting tirelessly to get more cultural sensitivity in Waterbury and all throughout the state," said Scot X. Esdaile, president of the Connecticut NAACP. "For them to do this at the end of the school year is totally absurd."

The district has been putting more emphasis on recruiting minority teachers, Schwartz said, and is developing a long-term strategy to interest more students in teaching.

"We have a long way to go with that," he said.

A Wilby High junior, Abbie Soto, said that the teachers from Waterbury generally connect well with students but that the same cannot be said for some others.

Brian Collazo, a 16-year-old student, said if it were up to him there would be no dress code. But, he said, "Some people do take it a little too far."