SINGAPORE - A man who was repeatedly spotted not wearing his mask properly on public buses lashed out at the drivers when caught.

William Aw Chin Chai spat in the direction of one driver on June 28 last year and hurled vulgarities at another about two months later.

He also targeted his fellow passengers, spitting at a woman on March 27 last year.

On another occasion in June this year, Aw shouted vulgarities at a man who was sitting near him.

Separately, Aw had also been caught pulling down his trousers and defecating into a plastic bag in a laundromat in April.

The 50-year-old Singaporean was on Thursday (Nov 25) sentenced to five weeks and 10 days' jail with a fine of $6,000.

He had pleaded guilty to nine charges for offences including harassment and using criminal force on another person.

The court heard that Aw was in bus service 162 at around 9am on March 27 last year when a 56-year-old Indonesian woman boarded the vehicle with her Singaporean husband, 60.

Aw suddenly stood up when she took the seat behind him and spat twice at her face, exclaiming: "You virus, go away."

Her husband then alerted the police.

Aw struck again on June 28 last year when he boarded SBS service 93 at around 12.30pm and was later spotted not wearing his mask properly.

The driver then stopped the vehicle at a bus stop in Ubi Avenue 1 to inform his employer's operation centre about the situation.

Aw scolded the driver after he heard this and was stepping off the bus when he spat at the man's direction, causing some of his spittle to land on the steering wheel.

On Aug 8 last year, Aw was seen wearing his mask around his chin when he boarded bus service 54 at around 6pm.

The driver asked him to wear it properly and Aw initially complied before he later pulled it down several times.

About 10 minutes later, the driver drove to a bus stop in Bishan and told Aw to alight as he had refused to listen to instructions. Enraged, Aw hurled vulgarities at the man before alighting.

The fourth incident took place on June 16 after Aw boarded bus service 32 at around 5.30pm.

He then used vulgar language to verbally abuse a man who was sitting near him.

In an unrelated incident, the court heard that Aw went to a laundromat in Eunos Crescent at around 2pm on April 6 to use its services.

Deputy Public Prosecutor Tay Zhi Jie said: "At about 3.16pm, the accused pulled down his trousers and exposed his buttocks. He partially squatted down and placed a yellow plastic bag at his buttocks.

"He then defecated into the plastic bag. Apart from the accused, no other person was present at (the laundromat)... but the incident was captured by (a closed circuit television camera there)."

For using criminal force on another person, an offender can be jailed for up to three months and fined up to $1,500.