"A policeman was patrolling close by and administered first aid until the ambulance arrived. The deepest wound just missed severing his spine.
"By some miracle no vital organs were damaged. We are praying that these animals are caught before they maim, or even kill, someone else. These are sad days."
In the last two months there have been 16 fatal knife attacks in the Capital, many of them believed connected to gangs. In total, 80 people were stabbed to death in the capital last year.
Hurley has praised the police and medics who have helped him.
In a tweet she wrote: "My 21 year old nephew was repeatedly stabbed in a brutal attack in London on Thursday night. The police & hospital are being fantastic. Thank you for all your messages. It is an appalling time for him & our family. The police will be appealing for witnesses."
Scotland Yard were called to the incident in south London at 8.52pm on Ascalon Street and are appealing for help in catching those responsible.
"Officers attended with the London Ambulance Service (LAS). A 21-year-old man was discovered with stab wounds to his back," a police spokesperson said.
"Another man, also believed to be aged 21, was also found suffering from stab wounds.
"They were both taken by LAS to a south London hospital where their conditions are described as not life-threatening or life-changing.
"They are believed to have been attacked by a group of males who got out of a vehicle and assaulted them before fleeing the scene.
"A crime scene was put in place. Road closures were also in place but have since been lifted. There have been no arrests."
Hurley flew back to Britain to be with her family.
On the day of the attack, Miles had paid tribute to his aunt in a post celebrating International Women's Day.
He posted a picture of her with another family member, writing: "Love & appreciation for all the strong, happy and independent women around me."
Hurley has previously shared Miles' modelling photos, tweeting: "Here's my handsome nephew."
