A local labour standards inspection office in Hiroshima has sent papers to prosecutors on Mazda Motor and a 51 year old factory manager over a blast at a plant in the city last October.

The office suspects that Mazda and the male manager failed to take appropriate measures to secure safety at the factory, Kyodo News reported.

The explosion occurred on 20 October at a shed to make cast-iron engine components. Melted iron that spilled from a toppled container reacted with water contained in nearby sand, causing a steam explosion.

Three workers suffered slight burns in the accident.

In a statement, Mazda expressed regret over the accident and said it would fully cooperate with the prosecutors.