SINGAPORE - Two teenagers were sentenced to reformative training on Thursday (Nov 26) for taking part in a brutal group attack on a 39-year-old man which left him bedridden and with brain damage.

Mohammad Zaidi Zahad, 17, and Muhammad Syazwandi Abdullah, 16, pleaded guilty to causing grievous hurt earlier this month.

The court had heard that at about 3.30am on March 6, the duo, together with two other friends, Ahmad Sholihin Mosa, 23, and Mohammad Noor Helmi Mohammed Herman, 19, went to the 7-Eleven store at Block 201E Tampines Street 23.

The victim, Mr See Chien Hwa, tapped Helmi on the shoulder to ask for cigarettes. But Helmi said he had none and Mr See went into the store to buy a drink.

When he came out, Mr See slapped Helmi on the back. Helmi asked him why, but Mr See did not reply. He then went to sit on a bench and started shouting at the group.

Unhappy that he had shouted at them, Helmi took 10 tablets of nitrazepam -a drug used to treat anxiety and insomnia - before picking up an empty glass bottle and asking his friends if they wanted to assault Mr See. They all confronted the victim.

Helmi swung the bottle at Mr See's head, then kicked his upper body, causing him to collapse.

Syazwandi, Zaidi and Sholihin joined in, kicking and punching Mr See in the face, abdomen, groin and knee repeatedly.

They left him bleeding on the ground, but Helmi returned to punch him repeatedly again. A passer-by later saw Mr See on the ground, covered in blood with glass fragments around him, and called the police.

Mr See suffered brain damage and remains unable to respond to verbal instructions. He is incapable of communicating verbally and physically.

A medical report in April said doctors are unable to guarantee his recovery. He was discharged from hospital last month, and has since been warded in a community hospital.

Sholihin and Helmi earlier this month also pleaded guilty to their offence. They will be sentenced next week.

Helmi also admitted to charges of drug use, theft, committing a rash act, criminal intimidation and arming himself with a dangerous weapon.

In sentencing Syazwandi and Zaidi, who also faced a charge of theft, District Judge Mathew Joseph noted the serious injuries inflicted on Mr See and the "vicious" nature of the assault.

He said: "It is quite astonishing what young people can do these days."

"You have to carry with you, in your conscience, what you have done," he said, pointing out that the assault inflicted permanent injuries on the victim, and diminished his life.

"I hope that you will realise what you have done and reflect on the gravity of the injuries that you have inflicted on the victim," the judge added.

A stint at the Reformative Training Centre lasts between 18 months and three years, and involves a strict regimen that includes foot drills and counselling.

The maximum penalty for causing grievous hurt is 10 years' jail, with fine and caning.