A view of the entrance to the Rikers Island prison complex. View Full Caption Spencer Platt/Getty Images

NEW YORK CITY — Federal prosecutors are suing the city over the "extraordinarily high level of violence" at Rikers Island — including "excessive" force by corrections officers and failing to protect young inmates from other inmates, court papers charge.

The stinging indictment of the Department of Correction, filed in Manhattan Federal Court, says the agency looked the other way in dealing with a culture of excessive force and failed to discipline officers who broke the rules.

"DOC staff have routinely used force unnecessarily as a means to control the population and punish disobedient or disrespectful inmates," the claim, filed on behalf of 16-18 year-old inmates, reads.

As a result, the young imates have been subjected to "serious physical, psychological, and emotional harm."

The lawsuit comes a day after Mayor Bill de Blasio visited Rikers Island jail for the first time and promised to put an end to solitary confinement for 16 and 17-year-olds inmates by the end of the year.

It also comes several months after Manhattan US Attorney Preet Bharara issues a wide-ranging report that cited a "systematic culture of violence" in the jail system.

Employees have used force as a form of retribution instead as a last resort, taken inmates to isolated locations with limited or no camera coverage to beat them up and put inmates in solitary confinement at alarming rates and for excessive periods of time, the 36-page long complaint reads.

The court papers cite a "staggering" rate of injuries - 754 in the year beginning in April 2012. About a third of those were head injuries, twice the rate of the adult population.

"The prevalence of head injuries is particularly striking," the documents say.

"DOC staff have regularly utilized headshots where no officer or other individual was at imminent risk of serious bodily injury and more reasonable methods of control could have been used to avoid such injury."