DALLAS (Reuters) - More than 200,000 children were hit as punishment in U.S. schools last year and in the South more blacks than whites are struck, two human rights groups said in a report released on Wednesday.

Teacher Darcy McKinnon teaches math to her seventh grade class at Samuel J. Green Charter School in New Orleans February 22, 2006. REUTERS/Lee Celano

Texas accounted for a quarter of the instances of corporal punishment in the 2006-2007 school year, according to the study compiled by Human Rights Watch and the American Civil Liberties Union.

The report, titled “A Violent Education: Corporal Punishment of Children in U.S. Public Schools,” plays into a debate in America about the effectiveness of corporal punishment and its role in the classroom and home.

Twenty-one U.S. states still permit the use of corporal punishment in schools. In Texas and Mississippi children as young as 3 are struck for transgressions as minor as gum chewing, the report says.

The punishment often involves hitting a child on the buttocks with a long wooden board, or paddle.

In 13 states in the U.S. South where corporal punishment is the most prevalent, African-American girls are twice as likely to be hit as their white counterparts, according to the 125-page report.

“African-American students are punished at 1.4 times the rate that would be expected given their numbers in the student population,” the groups said in a statement.

Citing U.S. Department of Education data, the report said 223,190 students nationwide received corporal punishment at least once in the 2006-2007 school year. This included 49,197 students in Texas, the largest number of any state.

Minority students already face several barriers to success, said Alice Farmer, the report’s author.

“By exposing these children to disproportionate rates of corporal punishment, schools create a hostile environment in which these students may struggle even more,” Farmer said.

Some U.S. conservatives view moves to ban corporal punishment in school and spanking at home as “liberal permissiveness” which can lead to bad behavior and wider social problems such as juvenile delinquency.

Many liberal groups regard corporal punishment as a barbaric relic of an unenlightened past that harms self-esteem and promotes violence.

“Every public school needs effective methods of discipline but beating kids teaches violence and it doesn’t stop bad behavior,” Farmer said.

The report documented several cases in which children were seriously injured and said students with physical and mental disabilities were subjected to disproportionate rates of physical punishment.

The report includes witness accounts including one from the mother of a 3-year-old in Texas who was bruised after being struck at school.

“What made me so angry: he’s 3 years old, he was petrified. He didn’t want to go back to school and he didn’t want to start his new school,” the mother, referred to as Rose T, was quoted as saying.