London police are investigating after six people were injured by a "noxious substance" thrown during a fight at a shopping center.
Saturday's incident at Stratford Shopping Centre was not being treated as terrorism-related, London's Metropolitan Police said.
"What initially may have been perceived as a number of random attacks has, on closer inspection, been found to be one incident involving two groups of males," Chief Superintendent Ade Adelekan said.
The groups fled the scene after the liquid was thrown, some into the nearby Stratford train station, the Met Police said in a statement. Six males had been hurt, the statement said, but none of their injuries were "life threatening or life changing."
A 15-year-old male has been arrested on suspicion of grievous bodily harm and is in police custody, the Met said.
"I recognize the lasting impact on victims of corrosive substance attacks. Our response to such attacks is continually improving through training and joint working with partners and we are working with the Home Office to explore possible restrictions around the sale of corrosive substances in conjunction with retailers and manufacturers," Adelekan said.
The London Ambulance Service said it was called to the scene just after 8 p.m local time.
"The first of our medics arrived within 10 minutes of the first emergency call and worked closely with our colleagues from the Metropolitan Police, British Transport Police and London Fire Brigade making sure patients received the medical help they needed as quickly as possible," spokesman Paul Gibson said. "We treated a total of six patients, three of whom were taken to London hospitals."
The ambulance service's hazardous area response team -- which provides medical care in hostile environments -- was involved in the response, Gibson said.