SINGAPORE - A repeat offender who molested two young girls on their way to school was sentenced to seven years' preventive detention and one stroke of the cane on Thursday.

Odd job worker Lee Kia Kit, 48, had pleaded guilty to two charges of outrage of modesty and had a third charge of molesting a 13-year-old boy taken into consideration.

A district court heard that the first victim, a 13-year-old girl, was on her way to school at about 6.35am on March 3 when she overtook Lee along a pavement in Bedok.

Lee approached her and whispered to ask her name and tell her not to be afraid. He then kissed her but she walked away. He only stopped following her when he saw a passer-by looking at him.

Two days later, he approached a 15-year-old schoolgirl at an open carpark in Bedok, placed his hand on her shoulder and repeatedly asked where she was going. Feeling uncomfortable, she did not reply and tried to leave but he continued to hold on to her.

He then got closer and touched her chest for a few seconds. The victim was so badly shaken that she stood there for some time - even after Lee fled.

Police eventually caught Lee after a search involving several teams of officers.

Deputy Public Prosecutor Paul Wong said Lee, who has committed offences spanning three decades, had been jailed before for similar sexual offences, adding that imprisonment has had no rehabilitative or deterrent effect on him.

While he noted that Lee has mild mental health problems, Mr Wong said Lee was "knowing and intelligent enough'' to pick young victims who were less intimidating and vulnerable.

He urged District Judge Ng Peng Hong to sentence Lee to preventive detention - which has no remission for good behaviour - for the protection and safety of the community. The maximum period of preventive detention is 20 years.