Hackers stole thousands of Bulgarians' personal financial data and distributed it from a Russian-based email in an attack possibly related to the purchase of new F-16 fighter jets from the United States, the government said on Tuesday.

The hackers accessed the National Revenue Agency's (NRA) systems on Monday before sending local media confidential information purportedly from Finance Ministry servers, Interior Minister Mladen Marinov said.

"Maybe this is the first case in Bulgaria which is successful and a lot of personal data has been stolen," Marinov told local TV channel.

He said the cyber attack was probably motivated by Bulgaria's move to buy eight new Lockheed Martin F-16 fighters for $1.256 billion from the United States, its biggest military purchase since the end of communism.