Police have arrested a 68-year-old man for suspected outrage of modesty of a 42-year-old female commuter while on a bus.

The bus was travelling along Kampong Bahru Road on Tuesday morning at about 8am when the woman felt someone touching her buttocks. Shocked, she immediately grabbed hold of the hand, and realised it was an elderly man.

The victim then alerted the bus captain, who reported the matter to the police through the bus operator. The man was later apprehended and police said investigations are ongoing.

Police have advised victims of molest to shout for help immediately, seek help from people nearby or activate a shrill alarm to increase the chances of apprehending the culprit early. They should also immediately call '999'. If found guilty, the man may be jailed up to two years or fined. He may also be caned.