If it were not for the police car and the centre's heavy iron gates, these young men with boyish faces would look just like any other students going to school.

In reality, they are juvenile delinquents and they will spend the next several years here.

There are now over 140 juvenile delinquents aged below 18 living in the centre, located in Songjiang District.

"Actually, there are far fewer inmates than there were at the beginning of the 1980s," said Shi Dinggen, the deputy office director of the Shanghai Prison Administration Bureau.

About half of the youngsters now in the centre are convicted muggers.

"Today's young men are not satisfied with a wallet or a bicycle," said Zhang Gulei, the director of the centre. "They're after bigger things like motorcycles and taxis.?

Most cases of mugging involving young offenders are committed by criminal gangs. "These young people draw strength from numbers,?Zhang said. "In reality, they are still timid and weak children.?

Pickpockets and thieves who have broken into houses account for the second largest group of offenders. Inmates who are rapists rank third.

For the first time in two years, the centre also houses young offenders convicted of drug dealing. Most of the drug offenders are from Northwest China's Xinjiang Uygur Autonomous Region.

"The source of the inmates' trouble is usually the family," Zhang said. "Over 20 per cent of children here come from broken families with divorced parents or have parents who have died."

Lack of love and care is a problem common to all these youngsters. One boy who is to be released next month has no family member willing to accept him. His divorced parents are both remarried and neither of them is willing to shoulder the responsibility of caring for him.

One 16-year-old inmate strangled his grandparents after his parents divorced. The grandparents were unwilling to let the boy live with them. The rejection precipitated a fierce quarrel, and the boy later murdered them.

"The behaviour of parents has a massive impact on children," Zhang said. "Parents of many of our inmates are gamblers or pornography addicts. Some actually instigate children to commit crimes."

Another boy in the centre has his parents and a brother all in prison.

"It's almost impossible for children to grow up a good person in such an environment," Zhang added.

Schools are also partly to blame, according to Zhang.

Schools concentrate on high-achievers in their classes to the detriment of those who are less strong academically, Zhang believes.

"Very few teachers make any effort with so-called 'bad students,"' Zhang said.

"We end up accepting the kids who have been abandoned by the schools as well as those who have been abandoned by their families.

"It is our job to help reform them. They are not treated like adult prisoners - education is the main method here rather than punishment. It is the principle we always follow," Zhang said.

Shi added: "In fact, reforming and helping these young men is the most important function of a country's juvenile supervision and education system."

Literacy classes and courses in computing, cooking, car maintenance and ironing are given.

"The aim is to give these children a skill which they can live on when they get out rather than having to resort to stealing," said Zhou Hejie, a teacher in the centre.

It seems the most popular interest of many of the inmates is computers. There are 189 inmates who have been awarded certificates for primary computer skill after passing the city's standard test in the past several years.

Several have even entered colleges and universities after being released from here. "Such successes are the happiest thing to me," said Zhang. "It is also a great encouragement to both children and officials here. We see hope and a future returning for them."

Officials call the juvenile delinquents "children." "Some children here even call the officials dad," said Zhang. "Often they will confide in us things they would not be willing to tell their parents."

Every Sunday afternoon, the telephone of Zhang' office keeps ringing. The "children" can talk with Zhang by telephone.

"They are still children and some of the things they say sound very childlike," Zhang said. Topics include suggestions for the following day's menu, quarrels with other children, reporting their marks and complaints about their relationships with their parents.

"Especially after the meeting for commuting of sentences, many children will want to promise me they will behave well," added Zhang.

The rate of inmates re-offending is very low compared with the rest of the world, Zhang said with pride.

"But society is still unwelcoming. They find it much more difficult to find a job or to continue their studies," said Zhang.

A 16-year-old thief, Zhang, was once a good student. Now his wish is to continue his studies after his release next January. But his former middle school and several other schools have declined his application, despite pleas from his parents. "I am now studying middle school courses by myself,?he said.

"It's the most distressing thing for me to see those who have re-offended sent to adult prisons when they have only just been released from here," Zhang said