SINGAPORE - Three youths had their scheme to rob a cabby all planned out - one would grab his neck from behind, the second would assault him, and the third would grab the money.

But when they did the deed in the early hours of Feb 2, they fled with a very small loot, and made a big mistake.

The coin pouch they managed to snatch contained only $5, and one of them left their iPhone in the vehicle.

On Tuesday, Muhammad Fauzi Fitri Kamaruzaman, 18, and Muhammad Aizan Abdullah, 17, were sentenced to probation in a community court after pleading guilty to robbing Mr Abdul Latiff Ismail, 53.

They were each ordered to perform 150 hours of community service, and their parents have to sign a $5,000 bond to guarantee their good behaviour. Meanwhile, a pre-trial conference has been fixed for their accomplice, Muhammad Istiqlal Hamdan, 18.

A community court heard that the three had boarded Mr Abdul Latiff's vehicle having planned to rob a the taxi driver. When the vehicle reached its destination, Fauzi, who was seated directly behind the driver, grabbed his neck. Aizan punched his face four times, while Istiqlal grabbed the coin pouch from their victim.

While fleeing the scene, Fauzi realised he had left his iPhone in the taxi. Agreeing to Istiqlal's suggestion that he report his phone had been lost, Fauzi went to the police station to say he had been assaulted and had lost his phone, wallet and watch.

The three were arrested later the same day. Investigations also revealed Istiqlal had thrown away the coin pouch, which was not recovered, while running away from the victim.

The penalty for robbery between 7pm and 7am can be a jail term of between three and 14 years, and up to 12 strokes of the cane.