Toyota announced another security data breach today, the second cyber-security incident acknowledged during a short period.

While the first incident took place at its Australian subsidiary, today's breach was announced by the company's main offices in Japan.

Toyota said hackers breached its IT systems and accessed data belonging to several sales subsidiaries.

The list includes Toyota Tokyo Sales Holdings, Tokyo Tokyo Motor, Tokyo Toyopet, Toyota Tokyo Corolla, Nets Toyota Tokyo, Lexus Koishikawa Sales, Jamil Shoji (Lexus Nerima), and Toyota West Tokyo Corolla.

Toyota said the servers that hackers accessed stored sales information on up to 3.1 million customers. The carmaker said there's an ongoing investigation to find out if hackers exfiltrated any of the data they had access to.

Customer financial details were not stored on the hacked servers, Toyota said.

"We apologize to everyone who has been using Toyota and Lexus vehicles for the great concern," a Toyota spokesperson said today in a message to the press.