Windows were shot on various floors of CDC buildings, officials said. Dickens said it was too soon to tell whether the agency had been targeted.

CDC director Susan Monarez, who started in her job this week, said in a social media statement that a gunman “opened fire on at least four CDC buildings”.

One of them, Building 24, is where the director’s office is, on the 12th floor. Monarez was not on campus at the time of the shooting – she had left earlier in the afternoon to return to DC, two agency officials said.

Monarez added that the organisation was “heartbroken” and that the campus remained locked down on Friday evening local time as authorities continued to investigate.

Officials said the shooter was found on the second floor of a building above a CVS. He had been struck by gunfire, although authorities said it was unclear whether that gunfire was from officers or self-inflicted. He died at the scene, officials said.

Police said they received a call about the shooting around 4.50pm Friday. At least 25 shots could be heard in the area, according to video shared with the Washington Post by a CDC employee.

Rapid-fire shots were heard near the CDC around 4.55pm, according to an employee who was on the 12th floor of Building 24 and spoke on the condition of anonymity because they were not authorised to speak publicly. Initially, they said, some people thought the shots were noise from construction.

The building was put on lockdown moments later, prompting the employee and their colleagues to lock the door and push chairs in front of the entrance. “We were all kind of in shock,” the employee said.

Looking out the window, the employee saw a person in a red shirt directing cars away from the scene of the shooting – “a hero” – the employee said.

The shooting took place near Emory Point, a mixed-use development with well-known restaurants and shops, as well as apartments, that sits across a busy road from the CDC campus. The Office of Critical Event Preparedness and Response (CEPAR) at Emory University, which is nearby, sent out an alert at 5.01pm urging people to “RUN, HIDE, FIGHT”.

In a statement, Georgia Governor Brian Kemp (R) praised first responders while decrying that “deranged criminals” had targeted Georgians in two incidents within a week. A US Army soldier allegedly shot five fellow service members yesterday at Fort Stewart.

“Marty, the girls, and I are thankful for all those who answer the call to serve and who protect their fellow Georgians,” Kemp said, referring to his wife, Marty, and their children. “We ask that you join us in holding them in our prayers, along with those harmed this evening near the CDC Centre.”

Georgia Attorney-General Chris Carr (R) said his office was “horrified” by the news and praying for the safety of Emory’s campus community.

“We stand ready to assist our law enforcement partners with whatever they may need,” he said in a statement.

The FBI’s Atlanta office said it was aware of the shooting and was co-ordinating with local law enforcement.