Potential gang members are being offered lifesaving first aid lessons, so they can help with victims of attacks.
The classes are being taught by volunteer doctors and medical students.
The youths are learning techniques such as stemming blood-loss with a tourniquet, perhaps from a belt, so they can keep causality victims alive till medical help arrives.
The Street-Doctors group believes that they can equip them with skills to help prevent victims from dying.
More top news
All the info you need to watch and get around London.
John Tomlin is convicted of two counts of inflicting grievous bodily harm with intent for throwing acid on Resham Khan and Jameel Muhktar.
Developers of a high-rise block that failed fire safety tests will pay for safety measures estimated to run into the millions of pounds.