President Lee Myung-bak pledged Monday to make electronic anklets more effective, expand the personal information disclosure of sex offenders and consider all possible measures against rapists, including chemical castration, as public outrage runs high over the recent kidnapping and rape of a seven-year-old girl.

Lee made the pledge during a biweekly radio address, calling last week's brutal rape, which left the girl with a ruptured rectum and other serious injuries, "a crime that could only have been perpetrated by a man with the mind of a beast."

A 23-year-old jobless man living in the girl's neighborhood in the southern city of Naju has been arrested and confessed to breaking into the girl's home and kidnapping and raping her. The court on Sunday issued a formal arrest warrant for the suspect, identified only by his surname, Ko.

"As president, I feel deeply devastated and regretful," Lee said. "What has to be done urgently in the short run is to increase the number of public security personnel on the scene. The government will work to muster all possible government authorities and police personnel to ensure public order and security."

Sex offenders tend to repeat crimes and the number of offenders considered at risk of repeating offenses amounts to about 20,000, Lee said, vowing to carry out a thorough investigation of their present condition, including their locations, and making them subject to priority control.

Lee also said the personal information disclosure of sex offenders will be further enhanced, and the effectiveness of electronic anklets will be bolstered. If these measures do not suffice, it will be necessary to "positively take into consideration all possible measures, including chemical castration," he said.

"The government will muster all its capabilities in order to prevent crime and secure the safety of the community. More than anything else, the government will crack down on violent crimes.

Particularly, we will strive to root out sex crimes against women and children," Lee said.

"I urge all citizens to cooperate with one mind in building a society where our children can play freely and women walk the street safely," he said. (Yonhap News)