Khoo Kim Hoon, 46, who was stationed in Surabaya, Indonesia, pleaded guilty earlier to touching the breast of the 17-year-old student on board SBS Transit No 168 along Seletar Expressway on Nov 14.

A district court heard that the victim went to the upper deck and sat on the right side of the bus on the third row from the staircase.

Khoo, who sat behind her, molested her while she was listening to music on her mobile phone through an earpiece.

Outraged, she immediately swept his hand away and turned around to confront him.

He apologised and pleaded with her not to call the police.

But she went ahead and told the bus driver who called the control centre for police help.

Khoo could have been jailed for up to two years or fined or caned or received any two such punishments.