Toyota Motor Corp. said Friday that data on roughly 3 million customers was stolen from its sales companies' computer systems in Tokyo following a hacking attack.

The data breach occurred earlier this month and was confirmed on March 21 at Toyota Tokyo Sales Holdings Inc.'s five affiliates and three other group companies. All are based in Tokyo.

The stolen data may include names, birth dates and employment information but not credit card numbers, Japan's top automaker said.

In a statement, Toyota apologized and pledged to thoroughly implement information security measures.