A coke addict who trained his pet dog to attack robbery victims on demand has been jailed for three-and-a-half years.

Elmi Said Elmi set his large Staffordshire terrier on a series of people in Battersea, stealing their mobile phones and cash and leaving the victims - including a schoolboy - with serious bites requiring hospital treatment.

Elmi, 19, of no fixed address, pleaded guilty to two counts of robbery when he appeared at Kingston Crown Court in September and asked for another three to be taken into consideration.

The court heard Elmi approached his first victim in Battersea Bridge Road shortly before midnight on December 13 last year and asked the 20-year-old student if he wanted to buy drugs.

The student refused but Elmi then demanded money, punched him and set the dog on him.

The victim was bitten several times on the arms before the dog was called off.

He was then made to surrender his mobile phone, wallet and cash card.

Elmi threatened to set the dog on the student again until he told him his pin number.

On March 31, Elmi and two other men approached a 24-year-old woman in Burns Road.

When she refused to give Elmi money, he commanded the dog to attack her.

The dog knocked the woman to the ground and Elmi took her handbag containing money and her mobile.

On April 20, Elmi tried to rob a 48-year-old female cyclist of her bicycle.

While the woman waited to cross Albert Bridge Road, Elmi started talking to her about his dog.

When the woman replied, Elmi shouted: "Attack her! Attack her!".

The dog leapt at the woman and bit her on the shoulder.

As she fought the dog off, Elmi tried to steal her bicycle.

When she kept hold of the bike, Elmi bit her himself, before members of the public came to her help and the would-be thief ran off.

On June 18, Elmi used the dog to rob a 13-year-old schoolboy of his blazer, mobile phone and money.

Elmi used the dog to force the boy behind a block of flats in Battersea Bridge Road, robbed him and ordered the Staffordshire terrier to bite him.

The boy suffered several puncture wounds to his arm.

Elmi's fifth victim was attacked by the dog after fighting back.

On June 19, Elmi forced the 20-year-old man against some railings in Dagnall Street and punched him.

When the man fought back, Elmi ordered the dog to again attack, biting the man on the arm, chest and thigh.

Elmi robbed him of cash and a mobile phone before running off.

Elmi was sentenced to three-and-a-half years for the attacks when he appeared at Kingston Crown Court yesterday.

Detective Inspector John McFarlane said aggressive dogs had in recent years "become a fashion accessory for some violent young men in parts of London".

"Elmi took this a stage further by training his dog to attack his victims," D Insp McFarlane said.

"This dog was used to terrorise innocent members of the public and it is fortunate that they have recovered from their physical injuries.

"These attacks were carried out in order to fund this criminal's cocaine habit.

"Since Elmi has been in custody there have been no similar incidents."

Police are still looking for the dog.