The bullet has been traced to the Japanese military

Jin Guangying, 77, came under fire in September 1943 as she was delivering lunch to her father, a soldier stationed in eastern Jiangsu province.

She could not afford a thorough examination, but her family recently borrowed money as her health worsened.

An X-ray revealed a 3-cm-long bullet thought to be of Japanese origin.

When she suffered from the headaches, she would sometimes babble words we could hardly understand, foaming at the mouth

Wang Zhengping

Mrs Jin was a 13-year-old girl when she was shot in the head in Xinyi County, Jiangsu, during a gunfight between Chinese and Japanese soldiers. She was one of the few survivors.

She recovered after three months, but went on to experience repeated headaches.

"When she suffered from the headaches, she would sometimes babble words we could hardly understand, foaming at the mouth, and sometimes she pounded her head with her fist," Mrs Jin's daughter told the Chinese state news agency Xinhua.

Doctors removed the rusty bullet after a four-hour operation.

"It's a miracle. The operation was not that difficult, but it's unbelievable that Mrs Jin was able to survive for such a long time with a bullet in her head," said Zhou Hong, the head of surgery at the hospital where she was treated.

Military experts in Nanjing said the bullet could only have come from firearms made in Japan.

The hospital refunded the cost of Mrs Jin's operation after the bullet was deemed a "piece of heritage", said her daughter.

But the family is planning to seek compensation and a public apology from the Japanese government.