A teenager sustained a cardiac arrest when he was being lasered by agents who tried to hold him in Coventry, police said.
The 17-year-old got CPR and rushed to the hospital after the Taser was used last night in the city of West Midlands.
He remains hospitalized in a "serious but stable" condition – while four other teenagers have been arrested by agents.
In today's statement, the West Midlands police said the boy had been thrown into an "attempt to hold him" after reports of a malfunction.
However, he needed "immediate" CPR when he got a cardiac arrest.
The armed forces said that three other 17-year-olds and a 13-year-old were arrested for violent disorder and attacking a policeman.
While two officers received "minor injuries" for which no hospital treatment was required, a windshield of a police car was shattered.
The incident was referred to the Independent Office for Police Conduct.
The statement read: "The police were called for reports of a failure in Prior Deram Walk, Canley, Coventry, just after 9.30 pm.
"A 17-year-old was Tasered in an attempt to hold him, but immediately required CPR if he went into cardiac arrest.
"He stays in the hospital in a serious but stable condition.
"Four other teenagers, three aged 17 and 13, were arrested for violent disorder and maltreatment of a policeman as a result of the incident."
It added: "Two male police officers suffered minor injuries that did not require hospital treatment and a windshield of a police car was destroyed.
"The incident was referred to the Independent Office for Police Conduct."