The FBI is searching properties in Antioch, Tennessee, a suburb of Nashville, and trying to determine if the human remains discovered after the explosion Christmas morning belong to the person living there, multiple law enforcement sources briefed on the investigation told ABC News.
Sources told ABC News the person in question is named Anthony Quinn Warner.
Federal agents arrived Saturday at locations connected to Warner in Antioch to conduct court-authorized searches, sources said. A Google Maps Street View image of Warner's address shows an RV in a fenced-in section of the yard that appears similar to the one used in the blast.
A neighbor told ABC News that an RV was often parked there.
"The RV's been there for a while; it doesn't really move. It just stays there. So this was something that looked suspicious that it's not there anymore," the neighbor, Hozan Rejab, said.
The man who lives at the property often kept to himself and seemed to live alone, Rejab said.
Warner transferred the title on the property last month for $0 to a Los Angeles woman, court records show. Law enforcement sources told ABC News the transfer is part of the investigation, as authorities work to understand the motive behind the RV explosion.
Law enforcement agencies have received nearly 500 tips after the parked RV exploded Friday morning, causing extensive damage.
"We are continuing to follow every lead we have," U.S. Attorney Don Cochran said during a press briefing Saturday afternoon.
FBI agent Doug Korneski declined to confirm at the time if a person of interest has been identified, but he said the FBI is "not looking for another subject."
"There are a number of individuals that we're looking at," Korneski said. "At this point, we're not prepared to identify any single individual."
Some of the evidence collected Saturday from the massive crime scene in Nashville was flown to the FBI crime lab in Quantico, Virginia, for forensic analysis, law enforcement sources told ABC News.
More than 250 FBI personnel from at least seven field offices are in Nashville working on the investigation, including special agents, analysts and professional staff, who are conducting interviews, collecting evidence and coordinating with partner agencies including the Bureau of Alcohol, Tobacco, Firearms and Explosives, and state and local investigators.
Post-blast investigators swabbed the scene for residue samples that will be sent for lab analysis to determine the types of chemicals used in the explosive device, law enforcement sources said.
The enormous crime scene has agents scouring not only at ground level, but on rooftops, some blocks away from the seat of the blast, for fragments that could help investigators piece together what happened on Christmas morning and why.
There are no known additional explosive threats at this time, authorities said.
"Nashville is safe," Metro Nashville Police Chief John Drake said during the briefing. "We feel and know that we have no known threats at this time against our city."
Authorities urged people to avoid the area, as a curfew is in effect until Sunday afternoon.
Drake asked residents and business owners to "be patient" Saturday while the investigation is underway.
"Just know that your businesses are safe," Drake said in a video address Saturday afternoon. "We have law enforcement officers at each corner to protect the area, so no one will be allowed access into your business."
Announcements coming from an RV said a potential bomb would detonate within 15 minutes, police said, before it exploded around 6:30 a.m. Friday, blowing out the windows of nearby buildings. The explosion is believed to have been an intentional act, authorities said.
Authorities are trying to determine why that location was selected for detonation and the composition of the explosive, sources said, and have been gathering samples to send to a lab for analysis.
Other investigators are working with behavioral analysts to understand what might have prompted somebody to commit the "intentional act" of blowing up the RV after warning people to stay away, sources said.
Officers worked to evacuate nearby buildings before the explosion. The department identified them Friday night as Officer Brenna Hosey; Officer James Luellen; Officer Michael Sipos; Officer Amanda Topping; Officer James Wells; and Sergeant Timothy Miller.
The officers were lauded as heroes during a press conference Friday, as they "took swift action and directed people away from danger," Nashville Mayor John Cooper said.
"The officers saved lives today," Drake also said. "They immediately began knocking on doors, not knowing if the bomb was going to go off immediately. They didn't care about themselves, they didn't think about that, they cared about the citizens of Nashville."
Tennessee Gov. Bill Lee also praised the "swift action" of Nashville police and local law enforcement after touring the site of the explosion Saturday morning.
"The damage is shocking and it is a miracle that no residents were killed," he said on Twitter.
Three people were taken to the hospital with minor injuries. Human remains were found at the scene, multiple law enforcement sources told ABC News. The remains have not been identified as of Saturday afternoon.
At least 41 buildings on Second Avenue were damaged, some extensively, authorities said.
Lee said he has requested an emergency declaration from President Donald Trump "to support ongoing efforts and relief."
The vehicle exploded outside an AT&T transmission building. Service continues to be impacted in Nashville and surrounding areas because of damage to its facilities.
A fire reignited overnight, leading to the evaluation of the building, AT&T said in a statement Saturday morning. Teams have drilled holes into the building in an attempt to reconnect power to critical equipment, and are also rerouting services to other facilities in the area, it said.
The company has set up two portable cell sites in downtown Nashville, "with numerous additional portable sites being deployed in the Nashville area and in the region," it said.
Because investigators still don't know if the telecom giant was the intended target, federal authorities have asked police around the country to increase patrols around AT&T facilities as a precaution.
"Due to the circumstances that took place Dec, 25th in Nashville, we ask that patrol divisions provide extra watch on any AT&T building located in any metropolitan building across the nation," according to the text of a federal bulletin obtained by ABC News. "AT&T partners with law enforcement, firefighters and first responders. We are public safety partners giving connectivity to agencies across the country."
The Federal Aviation Administration has issued a temporary flight restriction for Nashville, classifying the airspace as National Defense Airspace. Pilots who do not follow the restriction could be detained, the FAA warned.
The FBI and the U.S. Department of Justice's Bureau of Alcohol, Tobacco, Firearms and Explosives are leading the investigation.
The FBI is asking anyone with information to submit a tip on its website.
ABC News' Marcus Moore, Jeff Cook, Darrell Calhoun, Jenny Wagnon Courts, Josh Hoyos, Ahmad Hemingway and Sam Sweeney contributed to this report.