Two attackers on a moped pulled up alongside a 32-year-old man in the Hackney area of east London at 2125 GMT on Thursday and threw acid in his face before one of the pair made off with the victim's moped.
In the next hour and a half, three other men across Hackney and one in the neighbouring borough of Islington had corrosive substances hurled at them, police said.
After one of the robberies in Hackney, a man was left with facial injuries described by police as life-changing.
"A male in his teens has been arrested on suspicion of grievous bodily harm and robbery," the London police service said. "He is currently in custody at an east London police station."
"I don't want people to think that this is happening all over London all of the time - it's really not, but we are concerned because the numbers appear to be going up," Dick told the LBC radio station in an interview.
"Acid attacks are completely barbaric," Dick said. "The acid can cause horrendous injuries. The ones last night involved a series of robberies we believe are linked."
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