A full-time national serviceman was fined a total of $6,000 on Thursday for touching the buttocks of a woman and a teenage girl.

Xu Zhengxiong, 21, pleaded guilty to the two offences which took place at HDB blocks in Punggol in July and September last year.

A district court heard that a 41-year-old woman was outside her unit along the common corridor at about 10pm on July 5 when Xu came from behind and squeezed her left buttocks.

Shocked, she turned around and saw Xu standing behind her. She shouted for help and alerted her husband who gave chase but lost Xu who fled down the stairs.

On Sept 3, he struck again. He trailed a 14-year-old girl who was walking home near Punggol Plaza. When the girl reached her block and pressed the lift button, Xu followed her.

As she entered the lift, she suddenly felt someone touching her buttocks. Xu immediately retracted his hand and walked away briskly when she turned around. She went home and called the police. The court heard that on both occasions, Xu had worn a cap.

Xu was arrested the next day by a police ambush party. A third similar charge was taken into consideration. Xu could have been jailed for up to two years or fined or caned or received any two such punishments for each outrage of modesty charge.