Fourteen people were killed Friday in a running gunfight between police and suspects across three areas in Rio de Janeiro, Brazilian authorities said.
The violence took place in favelas (shantytowns) situated around Santa Teresa, a trendy bohemian neighborhood in the city's center.
Police did not provide any details on the fatalities, but the municipal health department was cited by state news service Agencia Brasil as saying that 13 suspects were pronounced dead on arrival at a Rio hospital, while the 14th died shortly afterward.
Two more people with gunshot wounds were being treated at the same hospital, according to the Agencia Brasil report.
The shooting began when police tried to carry out an operation against drug trafficking in the area, where criminal gangs are fighting over control of the market.
"Officers confiscated three rifles, 12 handguns and six grenades from the hands of criminals in Fallet, Fogueteiro and Coroa on Friday. Ammunition and transmitting radios were also found during the operation. We are on the streets!," Rio de Janeiro state police said on their official Twitter account.
Police said that rival gangs based in the Morros da Coroa and Fallet favelas have been engaged in street clashes since Wednesday.
Crime has traditionally been a problem in Rio state, but the violence sharply escalated after the city hosted the 2016 Olympics.
Nearly a year ago, then-President Michel Temer handed responsibility for public safety in Rio de Janeiro state over to the army, but the presence of troops did not address the structural causes of violence in the area, according to human rights organizations.
The data lab Fogo Cruzado (Crossfire), which maintains a real-time online map of shootouts in Rio, says that the number of shooting incidents in the Rio de Janeiro metropolitan area climbed 61 percent last year to 9,651.
Besides the increase in shootings, Fogo Cruzado points to a 40 percent rise in the number of civilians killed in police operations between February and December 2018 compared with the same period of the previous year.
Homicides fell just 5.5 percent despite the military deployment.
Nationwide, Brazilian police killed 5,144 people in 2017, when a total of 367 officers died violently.