An expert panel at Japan's health ministry said on Friday that it cannot rule out the possibility that a coronavirus vaccine caused the death of a 14-year-old girl.

This is the second time the panel has given such an assessment about the causal relationship between a vaccine and a recipient's death.

The girl got her third dose of US drug maker Pfizer's vaccine in August last year. She died two days later due to the inflammation of heart muscles or membrane.

Panel members say it is consistent to think the disease was caused by the vaccine, because she had no allergy or viral infections, and developed the inflammation of the heart and other organs soon after she got the shot.

The ministry has not disclosed her identity, but sources say she was a junior high school student in the western prefecture of Tokushima.

As a way to monitor the safety of vaccinations, the Pharmaceuticals and Medical Devices Agency looks into causal relationships between vaccines and side effects in suspected cases. The panel reviews its assessment.

More than 2,000 possible fatal cases have been reported, but most have been deemed unfit for assessment due to lacking sufficient details.

The panel previously said it could not rule out the possibility that a vaccine was a factor in the death of a woman from the central prefecture of Aichi. She died last November after getting a Pfizer vaccine.

The panel says at the moment it has no deep concerns about the vaccines' safety that could affect their rollouts.

But it asked the ministry once again to urge people to seek medical treatment quickly if they develop chest pain or breathing difficulties after getting a shot.