A hacker group based in Russia has attacked the Port of Nagoya, Japan's largest port by total cargo throughput and responsible for handling some of Toyota's exports and imports, the operator of the port's computer system said Wednesday.

The group, LockBit 3.0, has made a ransom demand in exchange for the system's recovery, Nagoya Harbor Transportation Association said, while police have launched an investigation.

The port has remained unable to load and unload containers from trailers, its operator, Nagoya Port Authority, said. It added that it intends to resume operations Thursday morning.