Multiple blasts in a park area of the Japanese city of Utsunomiya have killed at least one person and injured at least two people. 

Emergency officials say the explosions took place almost simultaneously at about 11:30 local time (02:30 GMT) in the city in Tochigi prefecture, north of Tokyo.

Although it was not immediately clear what caused the explosions, police officials confirmed that two cars in a nearby parking area also caught fire at the same time.

Kyodo news agency said a festival celebrating traditional culture had been taking place in a nearby park, where at least one of the explosions was reported to have taken place.

A man who was in the park at the time told Japan’s largest broadcasting organisation, NHK that he heard “a big sound” and smelled gunpowder.

The broadcaster also reported that a video camera at nearby Utsunomiya station recorded the sound of three explosions in quick succession at 11:31, 11:32, and a third “bigger sound” 15 seconds later.

Photographs showed a splintered and broken bench in the area of one of the blasts, while others posted to social media appeared to show a column of black smoke rising from the area.