A 17-year-old boy is in hospital after going into cardiac arrest when he was Tasered by police.
He was part of a group involved in a disturbance in Prior Deram Walk, Canley, Coventry, just after 21:30 BST on Saturday, West Midlands Police said.
Police Tasered the teenager in a bid to detain him, but he went into cardiac arrest and needed CPR. He remains in a serious but stable condition.
Four other teenagers were arrested on suspicion of violent disorder.
The teenagers, three aged 17 and a 13-year-old, were also held on suspicion of assaulting a police officer after the incident.
Two police officers also received minor injuries which did not need hospital treatment and a police car windscreen was also smashed.
The force said the incident has been referred to the Independent Office for Police Conduct (IOPC).