Story highlights There was a small explosion at a maintenance shop 
 
 A concourse was closed as a precaution, the fire department says 
 
 The FBI says it's not terror-related 
 
 A blast occurred at a maintenance shed at Hartsfield-Jackson International Airport in Atlanta on Tuesday morning, and part of a concourse was briefly evacuated, authorities said. 
 
 A small electrical explosion occurred around 8:40 a.m. near gate D21 at a "ramp level maintenance shop," the airport said in a news release. 
 
 "The cause of this explosion is currently under investigation. There were no reported injuries, and there was no fire," the airport said. 
 
 "There has been minor property damage. Passengers on the north side of Concourse D were evacuated to Concourse E. Arriving aircraft have been reassigned to other available gates." 
 
 The airport said the Atlanta Fire Department has since given the all-clear, and passengers were returning to Concourse D. A partial power outage remains in certain areas of the concourse, it said. 
 
 "Travelers should check with their airlines for any changing gate assignments," the airport said. 
 
 Janet Ward, an Atlanta Fire Department spokeswoman, said there was no fire and smoke at the shed. But, she said, an evacuation was made as a precaution on Concourse D and power was turned off. 
 
 Passengers who have since returned to Concourse D told CNN the situation there is normal. 
 
 FBI Special Agent Stephen Emmett said the incident doesn't appear to be terrorism-related. He said Atlanta police are taking the lead in reviewing the situation and the agency is not responding to the event. ||||| Virginia's Richmond International Airport is up and running again after a threatening phone call prompted an evacuation early Tuesday morning. 
 
 Virginia State Police say most flights at Richmond International Airport had been halted because a threatening phone call. Sgt. Thomas Molnar says the the call was received shortly after 6 a.m. 
 
 LOCAL REPORT: Terminal at Richmond airport evacuated after threat (Richmond Times Dispatch) 
 
 ALSO TUESDAY: Atlanta concourse reopened after 'small electrical explosion' 
 
 FROM MONDAY: Bomb threat diverts Southwest Airlines flight to Phoenix 
 
 Canine units have been brought in to sweep the terminals and the parking decks. The airport says in a posting on Twitter that sweeps of the terminals' public areas have been completed and nothing has been found. 
 
 But, as of 9:45 a.m. ET, Richmond airport says via Twitter that the terminal, "including airline desks and security screening, (has) re-opened to the public." 
 
 Molnar says the Federal Aviation Administration has been notified. ||||| RICHMOND, Va. (WAVY) - Richmond International Airport is in the process of clearing after the airport received a threat Tuesday, forcing an evacuation. 
 
 According to the official Twitter account of the airport, officials received a threat by phone that was serious enough to warrant an evacuation of the terminal as a precaution around 6 a.m. 
 
 Around 8 a.m., officials said K-9 units were about to go through the terminal to conduct sweeps. Numerous agencies were also providing mutual aid. Parking lots were cleared by 8:30 a.m. and passengers were allowed to get to their vehicles and leave. 
 
 The concourse was clear by 8:45 a.m. and the terminal cleared by 9 a.m. and reopened to the public by 10 a.m. Nothing was discovered. 
 
 Several flights scheduled for departure around 7 a.m. and 8 a.m. were pushed back to 8:30 a.m. or later. Check with airlines for more information on flights or to rebook if needed. 
 
 Further information was not immediately available. 
 
 Stay with WAVY.com for more on this developing story.
– Richmond International Airport was evacuated this morning around 6am following a phoned-in threat that was deemed credible, WAVY reports. Multiple federal, state, and local agencies and K-9 teams found nothing unusual in a search. At 8am, some 200 people stood about a quarter-mile from the terminal, the AP reports via USA Today; they appeared calm. Officials were "nice enough, just telling us they're clearing this, clearing that," says a passenger. At least a dozen flights were delayed, the Richmond Times-Dispatch adds, and the terminal was reopened at 9:30am. It's not the only aviation disturbance this morning: CNN is reporting that an explosion in a maintenance shed has shut down power to a concourse at Atlanta's Hartsfield-Jackson International Airport. The concourse was evacuated as a precaution.