CHANGCHUN, Jan. 20 -- Four kindergarten teachers have been arrested for using needle pricks as a form of discipline on more than 20 schoolchildren in northeast China's Jilin Province, the local procuratorate announced.

Parents in Siping City went to the police in November after they discovered red pinholes on their children's waists, legs and heads.

One victim had 50 pinholes throughout the body, a forensic test showed.

Five teachers were detained by the police at the time. The Red, Yellow and Blue Kindergarten was also closed by the local education bureau.

Four of the teachers were arrested for further investigation and one is out on bail.