A lockdown caused by a security alert at a nuclear processing site in South Carolina has ended, officials say.
The Savannah River facility was closed after a bomb-sniffing dog detected possible explosive residue on a truck.
But a US official told Reuters news agency that the site had since been deemed safe, though they were still investigating the delivery vehicle.
The facility, which is owned by the US Department of Energy, purifies highly enriched uranium.
Earlier, on its Facebook page, officials said an emergency response was under way and the site was closed to traffic.