Police are braced for an explosion of violent crime as gang rivalries and vendettas that have built up during the lockdown erupt onto the streets following the easing of restrictions, analysis by a leading criminologist warns. Dr Simon Harding, director of the National Centre for Gang Research at the University of West London, said the trading of social media taunts and drug feuds that have festered during the restrictions were likely to trigger an “explosive crimewave”. During the lockdown some gangs expanded their county lines operations and seized rival areas, escalating tensions with competitors who obeyed the government’s stay home measures and suspended trading. Harding, a former Home Office and Metropolitan police adviser, said: “We’re going to have the backwash of everything that’s happened over the last two months. There’s a crimewave coming, a tsunami on the way. “There’ll be increased rivalry and competition but there will be some amalgamation among county lines gangs, some will join as a business arrangement. It’s been a major shake-up, there will be winners and losers.” Fearing arise in attacks, the Met last week launched 12 new “violence suppression units” across the capital and identified 250 “micro-hotspots” as flash points. In addition, 1,000 of London’s most prolific violent offenders are being targeted by the force in an initiative to reduce stabbings. Although recorded violence fell significantly during the lockdown, a number of incidents since Boris Johnson announced an easing of measures last Sunday suggest old tensions have resurfaced. Last Wednesday, a 19-year-old was stabbed to death in Southwark, south London following a “large fight”. The following day, coordinated “violence suppression activity” saw police arrest 70 criminals who had used the UK’s road network during the lockdown. Outside London, some forces have predicted a return to gang tensions. In Birmingham, there have been warnings of a potential rise in violence after rival groups recruited “low-performing” children while out of school and are now preparing to exploit rising numbers of unemployed youngsters. Harding also warned that the increasing normality of face masks would assist rising levels of street crime, particularly robberies. “We are now in a position where legally and socially they can be masked up. Two months ago if someone approached me with a mask I’d either run or evade them somehow. Now that’s not going to happen.” Harding, whose book County Lines was published this month, said the criminal business model, in which young and vulnerable people were used as couriers to move drugs and cash between cities and smaller towns, was constantly evolving. Gangs in London, he said, had responded to the risk of being charged for trafficking offences when exploiting youngsters as “runners”. Instead they had begun recruiting drug users and in some instances had enticed them, rather than their own members, to inflict violence on rivals. “As well as child exploitation we are now seeing exploitation of vulnerable drug users. Some are being used as proxies to commit violence. If I’m a county lines manager and I want somebody taught a lesson then rather than send a boy I can just give two bags of brown to a heroin user to stab them. It’s horrible and manipulative.” Harding’s book details a series of phenomena about county lines including how disciplined London gangs deal in “asymmetric retaliation”, subduing provincial rivals with ferocious acts of violence. One county lines manager Harding interviewed claimed to be making £1,000 a day. A Lamborghini sports car worth £100,000 was among items seized last week by police targeting county lines dealers in the south of the capital.