NEW YORK — The number of murders in the United States rose 10.8 percent from 2014 to 2015, the largest year-to-year jump in at least 20 years, according to an annual report released Monday by the FBI.
There were significant rises in several large cities, although the murder rate remained about half the level from the 1990s, when violent crime reached a modern peak.
Overall, violent crime in the United States increased nearly 4 percent in 2015, according to the FBI data, but property crimes fell 2.6 percent.
A large percentage of the murders occurred in major cities, including Baltimore, Chicago, and Washington, that have been plagued by gun violence in some neighborhoods.
In 2015, Chicago reported 478 murders, up from 411 in 2014. Los Angeles had 282 murders compared with 262 in 2014. New York reported 352 murders in 2015, about 20 more than the year before.
In Massachusetts, the number of homicides reached a 10-year low last year. There were 133 homicides in the state in 2015, down from 146 in 2014, according to State Police and local police departments. In Boston, homicides dropped to 39 last year, from 53 in 2014.
The FBI report found that there were about 1.2 million violent crimes nationwide in 2015, up from 1,153,022 in 2014. Despite the increase, 2015 had the third-lowest number of violent crimes during the last 15 years, the data showed.
In 1996, a year in which cities across the nation were in the midst of a wave of violent crime, fueled partly by the crack cocaine epidemic, there were about 1.7 million violent crimes, according to the data.
Police officials and criminologists say there is no single reason for the rise in homicides in large cities, but point to minor disputes that more frequently end in gun violence and turf battles over the growing — and highly profitable — heroin trade.
‘‘The report shows that there was an overall increase in violent crime last year, making clear what each of us already knows: that we still have so much work to do,’’ Attorney General Loretta Lynch said Monday in Little Rock, Ark.
‘‘Violent crime endangers lives, destroys families and paralyzes neighborhoods. . . . In some ways, violence affects all of us — and so all of us have a responsibility to end it,’’ she said.
Although the FBI released its statistics on 2015 nearly 10 months after the year ended, a debate over crime has been raging based on the number of cities where homicides have gone up and, in some cases, surged dramatically.
Police departments in many of the places that saw homicides go up in 2015 say they have also seen increases so far this year, though officials and analysts have disagreed on the causes.
James B. Comey, the FBI director, has said that the increase in violence in some urban centers is partly the result of police officers being less aggressive in confronting potential criminality. Departments have been subjected to intense scrutiny over the last two years after fatal police shootings of African-American men and boys.
How police use deadly force reemerged as a national issue after an officer fatally shot a teenager in Ferguson, Mo., in 2014. Since then, protests have cropped up in cities nationwide, most recently in Charlotte, N.C., which just days ago saw violent demonstrations erupt after an officer fatally shot a man there.
In an analysis last week, the Brennan Center for Justice, a law and policy institute, found that Chicago has accounted for a remarkable share of the increase in homicides nationwide among big cities. Chicago, Washington, and Baltimore saw most of the increase in 2015.
There were also large differences among sections of the country, as the violent crime and murder rates in the South far outpaced those in the other regions. The FBI noted that 45 percent — nearly half of all murders — occurred in that region alone.
Once again, white people were far more likely to be killed by white people and black people far more likely to be killed by black people. One in five people were killed by an acquaintance, and almost half of all killings involved a single victim and offender, the FBI found.
Nearly 1 in 10 people killed in murders were younger than 18; more than 400 murder victims were younger than 5.
Among all of the violent crimes reported last year, guns were part of a sizable percentage, the FBI found. Guns were used in more than 7 in 10 murders, more than 4 in 10 robberies and a quarter of all aggravated assaults.
These FBI’s figures are released through its Uniform Crime Reporting Program, which collects numbers from more than 18,000 law enforcement agencies participating voluntarily. In addition to the crime figures, the FBI also collects data about how often police officers fatally shoot people, but these numbers are incomplete because of the voluntary reporting.