SINGAPORE - A freelance sales consultant who threatened a taxi driver and caused a dent on the bonnet of the tax was jailed for three weeks on Thursday.

Dickson Ng Ming Hao, 24, admitted to two of six charges of criminal intimidation and mischief.

A district court heard that Ng went to a shop in Simei to buy a knife on the evening of May 27 after a dispute with his then girlfriend, Ms Doris Ong Yen Ting, 24, at a food court beside Simei MRT station.

When Ms Ong saw the 20cm-long knife, she shouted at him and walked off to hail a cab. She got into Mr Goh Chong Yee's Trans-Cab taxi along Simei Street 3 without realising that Ng had followed her.

As the cabby Mr Goh, 46, was about to move off, Ng stopped him and pointed his middle finger at the victim. He then walked to Mr Goh's door, took the knife out and showed it to the victim.

Ms Ong came out to try and placate Ng. Despite Ng's earlier actions, the two of them eventually got into the rear passenger seat.

As Mr Goh was about to move off, Ng asked him in Hokkien if he was "scared or not" as he was holding a knife. He told the victim not to shake his head or he would "chop people''.

Ng, the court heard, also hurled vulgarities in dialect at the victim and opened the rear passenger door while the taxi was moving.

When Mr Goh told him not to make trouble, Ng shouted angrily that he was from a secret society and challenged the driver to a one-on-one fight.

When the taxi stopped along Tampines Street 31, Ng alighted. It is not known if Ms Ong alighted as well.

Ng then tried to open the front passenger door but Mr Goh had locked his doors. Ng then used the knife, wrapped in newspapers, to hit the front left bonnet, causing a dent which cost $535 to repair.

A private psychiatrist found Ng to be suffering from anxiety disorder. According to an Institute of Mental Health doctor, Ng had anti-social personality disorder, a history of abusing alcohol and getting sleeping pills.

Urging the court to sentence Ng to an appropriate jail term, Deputy Public Prosecutor Jason Nim said Ng had terrorised the taxi driver, caused damage to the innocent passive bystander's vehicle. Ng also showed wanton lack of concern for the public safety by committing the rash act offence which was among the four charges taken into consideration.

Ng also resorted to threats and weapons against Ms Ong and these were committed when he was out on bail, said Mr Nim.

He could have been jailed for up to two years and/or fined on each of the two proceeded charges.