SINGAPORE - A worker from a fast-food restaurant was jailed after he touched the thigh of a sleeping woman sitting next to him on an MRT train.

The woman kept her eyes closed at first as she thought she had made contact with a handbag belonging to another passenger, a court heard.

But Sun Lianjie was emboldened by the woman's lack of reaction and continued molesting her. She opened her eyes only after he touched her for the third time.

Sun, 22, was jailed for a week on Tuesday (Dec 26) after pleading guilty to one count of outraging a woman's modesty.

The Chinese national boarded a Circle Line train at Stadium station at around 9am on July 25 and spotted the 23-year-old woman.

The court heard that he found her "quite pretty" and placed his right palm on her upper thigh for a few seconds.

Deputy Public Prosecutor Tan Zhi Xiang said: "The victim felt some force on her thigh. However, she was not aware that the lady who was seated beside her had already alighted, and therefore thought that it was the lady's handbag which made contact with her thigh. Hence, the victim kept her eyes closed."

Sun continued molesting the woman. When she eventually woke up, she confronted Sun and told him that she would report the matter to the police.

The pair alighted at Nicoll Highway station and the woman approached a passer-by for help. Sun was then taken to the station control.

Mr Tan asked District Judge Jasvender Kaur to jail Sun for at least a week, noting that there has been a "disturbing increase" in the number of outrage of modesty cases on public transport.

He said: "The Singapore Police Force stated that between January and September 2017, there was a 19.9 per cent increase in the number of reported cases of outrage of modesty.

"Strikingly, there was a 49 per cent increase in the number of such cases committed on public transport."

Judge Kaur said: "The victim was in a vulnerable state and (Sun) took advantage of that."

Sun could have been jailed for up to two years and fined or caned for molesting the woman.