New York City jail guards reported more use of force against inmates in 2014 than ever before – an average of 11 incidents a day ranging from pepper sprayings to punches – amid heightened scrutiny from federal prosecutors to clean up what they call a “deep-seated culture of violence”.

Figures obtained on Wednesday by the Associated Press via a public records request show correction officers reported using force 4,074 times last year, including 406 incidents alone in September, the month after a scathing federal report that said Rikers Island guards too often resorted to force against teenage inmates.

“There has clearly not been a commitment to date to address officer violence on Rikers Island,” said Dr Bobby Cohen, a member of the jail oversight board who alluded to the record rates at a public meeting on Tuesday. “Will that change now? I hope so. I’ve certainly not seen that before.”

The figures come the same day federal prosecutors, who have since sued to speed up the pace of reforms at Rikers, begin three days of negotiations with city lawyers and correction officials over specific language on use-of-force policy, investigations and other jail problems.

Federal prosecutors declined to comment on the data. A jail spokesman said in a statement that city correction commissioner Joseph Ponte has a zero tolerance for excessive force and is updating the department’s use-of-force policy, improving staff training, expanding the investigation division and installing security cameras. He said those efforts and others likely will result in fewer incidents in the coming months.

Officers are required to fill out use-of-force forms every time there’s a confrontation with inmates, including when they are separating two or more inmates fighting each other. The data include the entire range of incidents from minor to serious use of force but don’t describe what happened in each case.

Use of force ranges from so-called Class C incidents such as pepper sprayings that result in minor to no injuries, to Class B incidents such as bruises and swelling that can be treated with over-the-counter care, to Class A incidents such as broken bones and deep cuts that require hospitalization.

Norman Seabrook, who heads the powerful 9,000-member Correction Officers’ Benevolent Association, said the rise in reported incidents was likely attributable to guards documenting more often than they did previously in an effort to cover themselves from potential lawsuits and discipline, even if they’re legitimately defending themselves from attacks.

“If I physically touch an inmate, it’s a use of force irrespective of an injury happening,” he said. “Absolutely we’re saying, ‘Document everything. Don’t physically get into an altercation but use chemical agents. Spray them. Spray everybody you’ve got to spray but don’t punch nobody out. Just spray whoever you’ve got to.’”

But inmate advocates and others point to the scathing August review by federal prosecutors that described a “deep-seated culture of violence” at Rikers, finding that guards regularly used physical force against 16- 17- and 18-year-old inmates often for perceived slights and signs of disrespect. The report said that behavior likely held true in all of the 10 facilities on Rikers, a massive jail complex in the East River that holds an average of nearly 11,000 inmates a day on charges ranging from trespassing to murder.

One such incident occurred last month, the week before a visit from Mayor Bill de Blasio, who has vowed to reform the nation’s second-largest jail system, according to an attorney for inmate Ambrorix Celeeomio.

Celeeomio, 18, who is being held on a gang assault charge, was pepper sprayed, punched and kicked by guards 9 December in a Rikers cafeteria without cameras after getting into an argument with a jail guard, according lawyer Jenay Nurse, who heads The Bronx Defenders’ Adolescent Defense Project. She said Celeeomio, who has an IQ of 65 and is cognitively delayed, was rushed to a Rikers clinic covered in blood.

A city official, who wasn’t authorized to speak about the incident, confirmed that Celeeomio was involved in the use-of-force with at least two correction officers that day.

The data also show use-of-force rates have increased steadily in the past eight years even as the overall inmate population has declined. Guards reported 3,285 uses of force in 2013 when the inmate population averaged 11,687. There were 1,299 reports in 2006 when there were nearly 14,000 inmates.

Plaintiff’s attorneys and others have long argued the city jails are consumed by violence and the AP reported last year based on a health department study that a third of inmates who said their visible injury resulted from a confrontation with jail guards suffered a blow to the head.

Inmate slashings and stabbings have also increased from a low of 19 incidents in 2007 to 93 last year, according to the data. But they’re down from a high of 1,552 incidents in 1990 when the jail population was 20,207 inmates.