TOKYO - One person has died and at least three others were injured as a result of multiple explosions that occurred at a popular park in the city of Utsunomiya in Tochigi Prefecture, north of Tokyo, on Sunday, local police officials said.

In Utsunomiya, the capital of Tochigi Prefecture, local police officials said that multiple explosions were heard in the vicinity of the Utsunomiya Castle Ruins Park and that at least three people were injured when the blasts went off in quick succession, during a popular festival where many people were gathered.

One person was found to be lying on the ground in the park after the first blast without vital signs when rescue officials arrived. His body was described by first responders as being "severely damaged" by the explosions.

One of the injured was rushed to a local hospital having possibly been struck by shrapnel from one of the explosions, although the extent of the victim's injuries is not yet fully known, local police also said, with rescue officials adding the person is receiving medical treatment.

Cars were also reportedly on fire in a parking lot close to the park following another explosion occurring quickly after the first, although no injuries have yet been reported as a result of the secondary blast.

Local police said the first explosion occurred at 11:30 am local time followed by the second around a minute later. A third explosion has also been reported by local media as occurring almost immediately after the second, although this remains to be confirmed by police officials, who have also yet to determine the cause of the explosions.

Witnesses at the scene, as quoted by local media, said the second explosion sounded smaller than the first, with the first being described by one witness as a "tremendous explosion similar to a bomb."

Others reported plumes of black smoke billowing into the sky from the parking lot after the explosions, and while police and local media have confirmed there were two explosions, some witnesses reported hearing as many as four or five loud blasts occurring in quick succession, according to some local reports.

Following the two explosions, eye witnesses also reported smelling what they described as gunpowder, according to Japan's public broadcaster NHK.

Utsunomiya lies 100 kilometers north of Tokyo and is an important cultural, political and economic hub in Japan and home to around 440,000 people and Utsunomiya City Hall is located close to the parking lot, thought to be the site of at least one of the explosions.

Due to its close proximity and ease of access from Tokyo by Shinkansen bullet train, the city and broader region are a popular destination for day trips by Japanese as well as foreign visitors.