Ministers have issued advice on how to spot children as young as 12 being used as drug mules.

The Home Office has published updated guidelines highlighting the problems of youngsters being exploited by gangs to run Class A narcotics and money around Britain.

The campaign focuses on the ‘county lines’ networks, where criminals use boys and girls as ‘couriers’ to flood small market towns and seaside resorts with heroin and crack cocaine.

The Home Office has published guidelines highlighting the problems of youngsters, some of who are as young as 12, are being exposed to by gangs

More than 1,000 county line gangs are believed to operate in Britain – a 40 per cent rise in just one year – making an estimated £1.8 billion annual profit between them.

The operations are named after the mobile phone numbers used to organise the illegal trade.

The guidance, updated yesterday as the Mail exposed the scale of the scandal, is aimed at parents, teachers, social workers, GPs and nurses, police officers and council staff.

It will enable people to understand ‘the nature of this harm... recognise its signs and respond appropriately to that potential victims get the help and support they need’.

It says county lines gangs, mainly based in cities including London, Merseyside and Manchester, ‘exploit children and vulnerable adults to move and store the drugs and money and they will often use coercion, intimidation, violence (including sexual violence) and weapons’.

It will enable people to recognise its signs and respond appropriately to that potential victims get the help and support they need

Police forces across the country say gangs are using machetes, boiling water, knives, bats and hammers, resulting in broken and even amputated limbs.

Children are lured into becoming mules by being promised hundreds of pounds a week, drugs or designer clothes, status, protection or perceived friendship or affection. Others get involved to stop someone carrying out a threat to harm their family.

The guidance says the majority of children recruited by county lines networks are aged 15 or 16.

White British children of both sexes are often targeted because gangs believe they are more likely to evade police detection, it says.

Social media, such as Facebook and Twitter, is used to make initial contact with children.

Police forces across the country say gangs are using machetes, boiling water, knives, bats and hammers, resulting in broken and even amputated limbs. Stock photo)

The ten-page document says criminals are known to target vulnerable children, including those who have been neglected or abused, come from broken homes, are homeless, linked to gangs or have mental health issues.

The advice says a young person’s involvement in county lines activities ‘often leaves signs’.

Those include persistently playing truant from school or going missing from home and unexplained acquisition of money, clothes or mobile phones.

Adults are urged to take note if a youngster receives excessive text messages, phone calls or has more than one phone.

How genteel cathedral city fell into grip of drug lords who are using children as their mules and 'bagging' (shooting in the buttocks) those who disobey them

The teenager who emerged from a park in Norwich in the early hours was in a pitiful state. ‘I’m dying,’ cried the youngster, who was bleeding heavily. ‘Someone help me, please.’

Moments earlier, families living opposite the popular wooded area, off West End Street, had been woken by the sound of gunfire and a car speeding away.

‘I was too scared to go out and help him,’ admitted a woman who saw the scene unfold from her bedroom window. ‘I’m a single mum with three children.’

The shooting a few weeks ago, police revealed, was the first time anyone in Norfolk had ever been injured from a firearm being discharged ‘in these circumstances’, an indication of just how safe Norwich used to be.

The brutal attack confirmed what detectives, councillors and residents knew perfectly well already: that the kind of violence and criminal activity normally associated with cities such as London, Manchester and Liverpool had spread to once sedate, law-abiding Norwich, almost on the edge of the Norfolk Broads.

Few details have emerged about the recent incident. The victim was 19 and came from London. He had been blasted in the back, it was reported (or rather, shot in the buttocks, according to our own inquiries).

Is this detail significant? Perhaps, because it may be a chilling clue to who was responsible.

Shooting someone in the buttocks (or slashing the buttocks with a knife) is a tactic employed by ‘county lines’ drugs gangs to humiliate and ‘mark’ rivals or punish disloyalty.

The perpetrators have a nickname for it: ‘bagging’ — a sickening reference to the fact that those wounded in this sadistic way sometimes need to be fitted with a colostomy bag.

Incongruously, Norfolk, perhaps more than any other area of the country, is engaged in a continuing war with these county lines gangs.The ruthless individuals who control the networks don’t live locally but are based in larger cities: many are at the other end of the M11, which links East Anglia to London.

Vulnerable teenagers, often in the care system, are used as ‘mules’ to transport heroin and cocaine, by train or car, to Norwich and surrounding towns and villages — in other words, from a saturated urban drugs ‘marketplace’ to an untapped rural one where there are vast profits to be made.

At the heart of the operation are mobile phone numbers, so-called county lines, which are circulated locally. Drugs are ordered in the same way you would ring for a pizza, and cut-price deals ensure there is no shortage of customers.

The new criminal phenomenon is having a devastating impact across Britain but especially in Norwich, which has an affluent professional class but also a burgeoning underclass.

It is the desperate and dispossessed who are mainly recruited to make drug deliveries, for money they could never hope to earn legitimately — or, in the case of young teenagers, sometimes for nothing more than a new pair of trainers.

Police admit that trying to tackle the threat is like cutting a head off the mythical serpent Hydra. As soon as one county line is closed down, another springs up.

In the past month alone, 25 county-line dealers have been jailed at Norwich Crown Court — no one believes they are the main players — and since 2016 more than 700 people suspected of county-lines involvement have been arrested in Norfolk, which is famed for its unspoilt lakes, beaches and wildlife.

The writer Virginia Woolf called it ‘one of the most beautiful of counties’.

The effect is corrosive. Parks have become meeting places for dealers and addicts, needles have been discarded in children’s sandpits, youngsters are approached on the way home from school by gang figures in vehicles with blacked-out windows who are eager to recruit them, and violence and intimidation have spread.

Almost every part of the city (population 213,000) has been affected by county lines.

The shooting took place north of the city centre, near the award-winning Fat Cat pub, which is popular with real-ale aficionados. It is near the ‘golden triangle’ where Norwich’s most handsome period properties, some worth more than £600,000, are found.

Sitting in the kitchen of one such elegant Georgian townhouse is a woman who runs a successful business from home. She does not wish to give her name, but she is part of a WhatsApp online messaging group called ‘Drugwatch’, formed with her neighbours to share intelligence about drug-dealing in the area.

‘Cars park up, young men on bicycles pull up alongside, then disappear,’ she said.

On her smartphone is a telling WhatsApp log for a few days in the summer when ‘activity’ was at its height.

The log begins at 09.47: ‘Dealer in silver sports [car] sitting waiting on Ampthill Street.’ 11.43: ‘Police arresting the dealer I saw this morning collect the drugs.’ 18.52: ‘Chap outside Oxford St waiting for someone. Kept checking phone. Looked dodgy.’

The scale of drug-dealing has declined because of the police response and the vigilance of residents. But the woman who started the WhatsApp group, a marketing executive, has had enough.

‘She lives near the lane [off Ampthill Street] where most of the drug-dealing is concentrated,’ said the businesswoman. ‘She has sold her home. It has been really upsetting for her.’

A knife was recently dumped in a garden in Ampthill Street, one of the most desirable addresses in the ‘golden triangle’.

The owner said he has given a statement to police and may be called to give evidence in a forthcoming trial.

In May, a man ran into the pharmacy in a parade of shops opposite Jenny Lind Park, just around the corner from Ampthill Street.

He wanted help for his friend, who had taken drugs in the park toilets and passed out.

‘We went to see what we could do,’ said Maziar Moaddabi, who runs the pharmacy. An ambulance was called and the man’s friend recovered. The police gave Mr Moadabbi a special telephone number, not generally available to the public, as a precaution.

‘They will arrive very quickly if I need them,’ he said.

The parade has become a well-known drug-dealing haunt. Claire Warnes, a sales assistant at a convenience store, is confronted with the reality of the drugs trade almost every day.

‘That’s where they ring up for the drugs,’ she said, pointing to a phone box outside. ‘You can hear them ordering the stuff.’

Then there are the teenagers used as runners to deliver the drugs, which are handed over to them from cars.

‘Sometimes I feel unsafe when lots of them come into the shop,’ said Miss Warnes. ‘They think they’re invisible.’ Many of them, she says, have been caught stealing on CCTV.

The transformation of Norwich is reflected in another set of figures. Of the 135 people who died as a result of drug misuse in Norfolk between 2015 and 2017, 45 were from Norwich, data from the Office for National Statistics shows.

The only other towns in the UK with a higher rate were Swansea, Port Talbot and Hartlepool.

Nowhere is the dark side of Norwich more obvious than in Chapelfield Gardens in the city centre, just yards from the Theatre Royal and upmarket shops and restaurants.

The gardens date from the 1880s and there is still a Victorian bandstand in the middle of them.

Did the park have a drugs problem, we asked a middle-aged resident who lives in a house overlooking the gardens.

‘Oh my God, yes,’ she replied. ‘This year has been the worst ever.’ She has even seen drug deals taking place on the bandstand. ‘It’s blatant,’ she said.

The kiosk, serving tea and refreshments, is where dealers often congregate. They are easy to spot, she says. They are young, some no more than 14 or 15, and all on pushbikes.

‘They talk like gangsters,’ said the resident. ‘They’re all in the latest gear and fancy trainers. They have manbags stuffed with cash and show off by pulling out wads of cash when they pay.’

These youngsters are victims themselves. Many come from care homes and were sucked in by county-lines gangs, police told us.

One such teenager has just come before Norwich Crown Court. He was running his own county line called ‘Carlos’. And police have identified other county lines, each making around £5,000 a week, with names such as ‘Ninja’, ‘Rico’ and ‘Chris’.

This particular youngster, who was 17 and in foster care, was ‘heavily involved in dealing Class A drugs’, the court heard. He was jailed for two years and eight months after being caught by an undercover officer who first encountered him in Chapelfield Gardens in March.

On Wednesday last week, three boys were sitting on the back of a bench about 100 yards from the café, smoking cannabis. ‘They’re CID,’ they could be heard saying as we approached.

When they established that we weren’t police and got talking, it emerged that two of them were from children’s homes. They insisted they were not dealers. But they had no family to speak of.

Sadly, it is frighteningly easy to see why youngsters like this choose a ‘career’ in county lines.

Almost everyone we spoke to said Chapelfield Gardens was a haven not just for dealers but for addicts, who openly take crack cocaine and inject heroin.

Horrified residents said that discarded needles are sometimes left with the points sticking up, as if deliberately planted in the ground to cause injury. They have been found in Chapelfield Gardens, at the bottom of a nearby children’s slide and in a sandpit at the top of Silver Road.

In Norfolk, offences involving violence against the person rose from 8,294 in 2013 to 18,002 in 2017. This, police say, has been fuelled by increased drug activity resulting in ‘turf wars’ between rivals.

In Chapelfield Gardens, one man had his teeth knocked out by county-lines thugs for peddling cannabis.

‘People are scared,’ said Jane Watkin, a beauty therapist who chairs the newly former Russell Street Community Area Residents Association. ‘People have been beaten up in the street with baseball bats and drug dealers are being arrested outside our front doors.’

Back near West End Street, the mother who heard the shooting recalls that the victim stumbled against her front door before staggering off down the road. ‘The door was wide open when I went downstairs,’ she said. ‘His weight must have forced it off the lock.’

Her 17-year-old daughter has something to relate too. One night a few months ago, she said, she was walking home with friends when a car pulled up alongside them. The driver asked if they knew where he could get weed [cannabis].

He also mentioned cocaine.

‘No,’ they replied. He then asked the two boys in her group if they could ‘do him a favour’ and suggested they go for a drive and ‘have a chat about how they could help him out’. They politely turned down the request and he drove off.

‘It was quite clear what he wanted them to do,’ the woman’s daughter said.