A 71-year-old man was charged yesterday with harassing and assaulting a foreigner on board an MRT train in April this year.

Gan Thean Soo is alleged to have used abusive words on Mr Joseph Flynn De Marini, 25, at about 8.30pm on April 19. Gan was on the train heading towards Farrer Park station when he allegedly told Mr De Marini that he was gay and wanted to have sex with him.

Mr De Marini, who is American, captured the exchange on a video clip which went viral after he uploaded it on Facebook.

Gan could be heard saying: "Singapore is not like America; we can touch you."

Despite other passengers intervening, Gan allegedly continued heckling Mr De Marini.

Five minutes later, he is said to have slapped the American on the left side of his head. The third charge states that he caused annoyance by raising his voice at Mr De Marini during the train journey.

Gan, who is represented by Mr Philip Loh, was remanded at the Institute of Mental Health for psychiatric observation.

He will be back in court on Dec 1.

If convicted of harassment, Gan could be fined up to $5,000 and/or jailed for up to six months.

The maximum penalty for causing hurt is two years' jail and a $5,000 fine; and for committing public nuisance, a $1,000 fine.