Two boys, ages 15 and 16, were arrested in connection with the attacks, committed during a 72-minute spree Thursday across the neighborhoods of Clapton, Hackney, Islington, and Stoke Newington in northeast London, Metropolitan Police said.
According to the Metropolitan Poloce Services, the five victims were transported to hospitals, with one man suffering life-changing facial injuries.
The attacks were linked and police are questioning the teenager at an east London police station on suspicion of robbery and causing grievous bodily harm.
At 11:05 p.m., a corrosive substance was thrown in the face of man by two males on a moped on Shoreditch High Street.
Police said the man went to an east London hospital and they are waiting for an update on his injuries. His injuries were not life-threatening, police said.
The number of reported attacks using corrosive liquids rose from 261 in 2015 to 454 in 2016, London police said.
Police received reports of the fourth assault at 11.37pm, when another man was confronted as he sat on his moped in traffic on Chatsworth Road.
Click to enlarge Map showing London acid attacks
Five separate male victims, all on mopeds, were allegedly targeted by two attackers also on a moped.
"We can confirm that one of the victims of these attacks had been taking food to a Deliveroo customer", a spokesman said.
Shadow home secretary Diane Abbott said: "With very few prosecutions it is clear that we do not have the tools necessary to investigate and prevent these attacks".
Politicians have called for new legislation to regulate the sale of cleaning products most commonly used as weapons, and appeals to manufacturers to change the formula of corrosive cleaning products to make them more viscous so they can't be easily flung or sprayed at victims. "They took out two large water canisters and poured it over him".
The police on Friday arrested two minors for their alleged involvement in the string of acid attacks that ripped London on Thursday in just over an hour.
Just a week before, the simillar incident happened, a man threw acid in the face of an aspiring model and her cousin in east London.
"There was a really frightening screaming", he said.