Firefighters put out a fire late Thursday at a nuclear waste processing facility in central Japan, a trade ministry official said, adding that no one was injured in the blaze.

The government’s monitoring post near the Hamaoka Nuclear Power Plant along the Pacific Coast in Shizuoka province, some 180 kilometers (112 miles) west of Tokyo, detected no leak of radioactivity, the official said.

The fire broke out at 9:10 pm (1210 GMT) at the underground facility on the premises of the five-reactor plant, but it was extinguished by 10:40 pm, he said.

“Shizoka Prefecture and our agency will conduct an on-site inspection tonight in order to determine the cause of the accident,” said Hidehiko Nishiyama, director of the policy planning and coordination division at the ministry’s nuclear and industrial safety agency.

“I cannot say how serious it is compared with other accidents until we get more details,” he said.

Operator Chubu Electric Power Co. Inc. said a container carrying melting low-level nuclear waste was knocked over while being ferried on a conveyer belt, according to company spokesman Shigehisa Osawa.

The facility is designed to reduce the volume of waste before disposal.

“We cannot confirm how many people were working at the facility at the time but we have confirmed that nobody was hurt,” said Osawa.

A report to the ministry said an unspecified number of workers were at the site and witnessed the accident through a glass shield, Nishiyama said.

Three of the five reactors are in operation while the remaining two were shut down for routine checkups, Chubu Electric said on its website.

Resource-strapped Japan depends on nuclear power generation for about 30 percent of its total electricity needs. The other key power sources are liquefied natural gas and hydro-electric power.

Japanese companies have come under fire for a string of accidents at nuclear power plants in recent years caused by human error and poor maintenance.