Japanese car giant Nissan warned customers Thursday that its operations in Australia and New Zealand had been hit by a "cyber incident".

Nissan said it had notified the national cyber security centres in both countries, while the company's global response team assessed the scale of the attack.

It was unclear whether any personal information had been accessed, the company said in a statement.

"While the extent of the incident is still under investigation, Nissan encourages its customers to be vigilant across their accounts, including looking out for any unusual or scam activities," the statement added.

The incident had so far not affected its dealer network, Nissan said, adding that it was working to restore its systems.

Nissan has 83 dealers in Australia and 33 in New Zealand, a company spokesperson told AFP.

The car company sold around 3.2 million vehicles worldwide in the fiscal year 2022/23. Their main markets are North America, China, Japan and Europe.

Nissan announced last month in Tokyo that it expects to make a net profit of 390 billion yen (US$2.6 billion) for the year to March 2024, on sales of 13 trillion yen.