SINGAPORE - Four motorised scooter riders went to find a man one of them had collided with in a park and beat him up.

They might have got away with it had one of them not lost his phone in the fight - for when Tan Wee How later tried calling his own number it was answered by a police officer.

All four were swiftly arrested and on Monday (April 30) they were sentenced to jail for attacking Roman Barros Griffiths.

The 45-year-old Argentinian was walking with his wife in Bishan Park 1 late on February 10 last year when the four men rode towards him after sharing four bottles of beer at a coffee shop.

He raised his arm to signal them to stop so he and his wife could cross at a junction.

But they rode past and the final rider, Ng Yeow Tim, 40, bumped into Mr Griffiths' arm. An angered Ng confronted Mr Griffiths and an argument broke out. The court heard that they exchanged angry words before Ng rode away and told his friends what had happened.

They decided to look for Mr Griffiths to settle the score and spotted him about 10 minutes later. When Ng shouted at him, Mr Griffiths said he would call the police.

Tan suddenly ran towards the Argentinian and punched him in the head three times.

Mr Griffiths tried to escape but the three other attackers caught up with him, punching and scratching him before he eventually managed to break free and call the police.

Mr Griffiths' wife had told the group to stop the attack but Tan kicked her leg, causing her to fall. The men fled and she found Tan's phone which she handed to the police.

Deputy Public Prosecutor Teo Lu Jia said: "When Tan called his own mobile phone, a police officer answered. Tan subsequently returned to the scene... and he was identified as one of the assailants in this case by the victim."

Mr Griffiths suffered bruises to his head and left shoulder.

Ng was jailed for a week, as was Thomas Leong Sin Kwang, 37, while their fellow Singaporean Tay Woei Chain, 28, will be spending two days behind bars.

Tan, a 34-year-old Malaysian was sentenced to two weeks' jail and had a second assault charge for kicking Mr Griffith's wife taken into consideration during sentencing.

He was offered bail of $5,000 as he wishes to settle his personal matters before serving his sentence. He must surrender himself to the State Courts on May 14.