May 7 (UPI) -- At least 84 people were shot in Chicago over the past week -- another surge in gun violence in the United States' third-largest city, which may have been brought on by warmer weather.
Of those wounded, nine died, and police said at least 41 people were shot over the weekend alone.
The shooting victims involved involved children, including a 12-year-old boy, and a federal agent with the Bureau of Alcohol, Tobacco, Firearms and Explosives.
The uptick of violence in Chicago came as the Chicago Police Department expressed optimism about a downward trend in gun violence in recent months.
For the first four months of this year, Chicago saw a 22 percent drop in gun-related homicides and a 26 percent drop in shootings overall compared with the same four months of 2017. Officials said April marked the 14th consecutive month in which Chicago recorded a decline in gun violence.
Authorities believe warmer weather may have played a role in the surge last week. The colder months may have slowed gun violence, as the city this year endured its fourth-coldest April ever.
Chicago, along with a number of other cities, is expected to see warmer-than-normal temperatures this week.
The injured ATF agent was shot in the face Friday, but is expected to make a full recovery.
"We will find you," CPD Supt. Eddie Johnson told the shooter, who has not yet been captured. "We will knock on every door, talk to every witness, watch every piece of video and analyze every piece of evidence. Believe me, you will not get away with this."
Johnson ordered a manhunt to find "anyone involved in this reprehensible crime."
The FBI and ATF have each offered $25,000 for information in the case, and the U.S. Marshals Service $10,000.