US investigators have identified a person of interest in connection with the explosion that rocked the centre of Nashville on Christmas Day and are searching a house in the city’s suburbs, the FBI has said.
Officers raided a home in Antioch after receiving information relevant to the investigation, according to FBI special agent Jason Pack.
Another law enforcement official said investigators regard a person associated with the property as a person of interest over the explosion.
Earlier, investigators said they were looking at a number of individuals who may be connected to the blast, but have also found no additional explosive devices – indicating no active threat to the area.
Douglas Korneski, the special agent in charge of the FBI’s Memphis field office, said 250 agents, analysts and FBI staff are making progress in the search for the person or people responsible for planting a bomb in a campervan that exploded along a mostly deserted street.
Three people were injured in the explosion.
He said: “It’s just going to take us some time,” adding that his team would turn over every stone to find out who was responsible, and why.
Separately, the US Federal Emergency Management Agency said that tissue samples found at the scene were determined to be human remains.
The attack continues to wreak havoc on communications systems across the state.
Police emergency systems in Tennessee, Kentucky and Alabama, as well as Nashville’s Covid-19 community hotline and a handful of hospital systems, remain out of service due to an AT&T central office being affected by the blast.
The building contained a telephone exchange, with network equipment in it – but the company has declined to say exactly how many people have been affected.
Investigators shut down the heart of downtown Nashville’s tourist scene – an area packed with bars, restaurants and shops – as they shuffled through broken glass and damaged buildings to learn more about the explosion.
City mayor John Cooper has enforced a curfew in the city centre area until Sunday via an executive order.
AT&T said restoration efforts are facing several challenges, which include a fire that “reignited overnight and led to the evacuation of the building”.
This has forced their teams to work with safety and structural engineers and drilling access holes into the building in order to reconnect power.
Tennessee state governor Bill Lee asked the White House for federal assistance due to the “severity and magnitude” of the explosion’s impact.
At least 41 buildings were damaged, and communications systems — including residential and mobile phone service and emergency call centres — failed across the state, he said.
Kentucky and northern Alabama were also affected, he said.
Ray Neville, president of technology at T-Mobile, said on Twitter that service disruptions affected Louisville, Nashville, Knoxville, Birmingham and Atlanta.
“We continue to see service interruptions in these areas following yesterday’s explosion. Restoration efforts continue around the clock & we will keep you updated on progress,” he said in a tweet.
The outages had even briefly grounded flights at the Nashville International Airport, but services are continuing normally as of Saturday.
The Federal Aviation Association has since issued a temporary flight restriction around the airport, requiring pilots to follow strict procedures until December 30.
According to Metro Nashville police chief John Drake, police officers were responding to a report of shots fired on Friday morning when they encountered the campervan blaring a recorded warning that a bomb would detonate in 15 minutes.
Police evacuated nearby buildings and called in the bomb squad. The vehicle exploded shortly afterwards.
Law enforcement officials have said since shortly after the explosion occurred at around 6.30am that they believe the blast was intentional. They have not talked publicly about a possible target or motive.