The youth, named locally as Hakim Sillah was killed after a fight broke out during the event at the Youth Offending Service at Uxbridge Civic Centre

An 18-year-old stabbed to death in west London was attending a council-run knife awareness course at the time it has emerged.

The youth, named locally as Hakim Sillah was killed after a fight broke out during the event at the Youth Offending Service at Uxbridge Civic Centre yesterday.

He suffered a critical stab wound and died less than an hour after being airlifted to hospital.

A second boy, 17, was arrested and remains in custody. Officers are not looking for any more suspects.

Officers have branded a third boy, 17, 'amazing' after he was also stabbed as he stepped in to break up the fight.

He was taken to hospital for treatment but has since been discharged.

The officer in charge of the case said that the boys attending the course were all young offenders and were there by appointment but he was not aware of any specific security at the event.

Forensics officers were seen outside the local Youth Offending Service after yesterday's stabbing in Uxbridge

A tribute to Hakim left outside the Hillingdon Civic Centre after he was stabbed to death there yesterday

The Conservative-led council is in the constituency of Prime Minister Boris Johnson.

A Met Police spokeswoman said: 'The event was a knife awareness course.'

DCI Noel McHugh, leading the investigation, said that as far as he knew the young men attending the event weren't searched for weapons.

He said: 'They were in the Civic Centre and were all young males. They were there by appointment. They were young offenders.

'It was a group session and a very quick altercation occurred between two individuals which resulted in one mail sustaining a knife injury which would cost him his life.

'My understanding is that it was a council event and there was no screening process but my understanding is that they would have carried out their own risk assessments.'

However, he added: 'I wasn't there, they may have done.

'During the attack an independent unconnected male tried to intervene and break up the fight and that male sustained a stab injury. He has been treated and has since been released from hospital.'

The Met has not yet commented whether any confrontation happened inside the Youth Offending Service

A forensics officers taking a photograph near the scene of yesterday's stabbing on Uxbridge High Street

DCI McHugh said the victim's family are 'broken, absolutely broken'.

He added: 'Obviously this isn't their words, it's my interpretation. I met them last night and they are absolutely broken - it doesn't feel real.

'What we can say is that as a result of very quick policing response this individual was traced and arrested and is currently in custody and will be interviewed this afternoon.

'It's very early days. We are speaking to witnesses and are understanding what actually took place.

'It is not known if they were known to each other. We're looking into their lifestyle and their associations.'

Staff and others attending the event have been trying to cope with the horrific incident.

DCI McHugh said: 'The individuals we have spoken to are absolutely shocked and are coming to terms with the loss of such a young life so tragically.'

The weapon used in the attack has not been found.

Anyone who witnessed the incident or has information is asked to call police on 020 8785 8099, tweet @MetCC or call Crimestoppers anonymously on 0800 555 111.