A 14-year-old boy has been arrested after an acid attack which left a delivery driver in a life-threatening condition and likely to lose sight in both eyes.
The boy was held on suspicion of grievous bodily harm in relation to the attack in Walthamstow, east London.
At around 6pm on Thursday, the fast food delivery driver was approached by two men on a scooter in Walpole Road.
The men attempted to steal the victim's moped and police believe a corrosive substance was then repeatedly thrown into the his face.
The victim, a 32-year-old man, was treated at the scene and taken to an east London hospital.
Detective chief inspector Gordon Henderson said: "This attack has left a man fighting for his life and with terrible eye injuries.
"This was an innocent man going about his work as a delivery driver, who may never see again.
"This is not a time to hesitate - if you have any information about this crime I would appeal that you immediately call police."
Police are also investigating an identical acid attack which occurred around half an hour later, in Yarmouth Crescent in Tottenham, north London.
The second victim, also a 32-year-old delivery driver, was approached by two men on a scooter who attempted to steal his moped and sprayed a corrosive substance on his face.
The victim was taken to hospital but his injuries are not believed to be life-threatening or life-changing.
It is not yet known if the two attacks are linked, but it is an active line of inquiry and detectives in Tottenham and Waltham Forest are working together.