A Port of Long Beach terminal affiliated with Cosco Shipping has been hit by a ransomware attack - but the incident has not derailed operations, according to a port spokesman.

"Ships, trains and trucks are coming in and out as usual," Lee Peterson told TradeWinds today.

"As of this point, because perhaps Cosco has a separate terminal operating system, the attack has not affected operations at the terminal."

Port officials and the US Coast Guard are monitoring the Tuesday attack and keeping contact with Cosco, he said.

"We take cybersecurity very seriously," he said.

Peterson said the incident is the first cyber attack at the Long Beach port, recalling the incident at Maersk offices worldwide in late June 2017 that cost the Danish company $50m.

"That was a very serious situation and you know these things can happen," he said.

Cosco has sent a letter to its customers to notify them of the attack.

"Due to the local network breakdown within our Americas region, local email and network telephone is not working properly at the moment," the company said.

"For safety precautions, we have shut down connections with other regions for further investigations."

Cosco said all of its vessels "are operating normally, and our main business operation systems are stable" following the attack.

The business operations in the Americas are still being carried out, and we are trying our best to make a full and quick recovery," the company said.

"We are glad to inform you that we have taken effective measures and aside from the Americas region, the business operation within all other regions will be recovered very soon."

A call to Cosco was not immediately returned.