A public park in Tokyo has been closed after dangerously high level of radiation was recorded from close to the playground equipment on Thursday, which officials suggested could be originating from radioactive material buried underground.
Radiation levels of up to 480 microsieverts per hour were recorded from the Ikebukuro Honcho Densha no Mieru Koen park. The level is almost half the safety limit of radioactive exposure for a person in a year.
A local alerted authorities at the Toshima Ward Office earlier this week, and they recorded high radiation level close to the ground next to the playground equipment in the park.
"Because the area in which we detect radioactivity is very limited, and readings in the surrounding areas are normal, we suspect radioactive materials of some kind are buried there," Toshima Mayor Yukio Takano said in a statement.
The park had opened in 2013, and the site was earlier used as a parking lot for garbage collection vehicles, according to The Japan Times.
"Many children play in the park daily, so the ward office should explain the situation," a resident told the media.
Authorities have begun the process to decontaminate the area.
The findings have sparked fear days after a drone with levels of radiation had landed on the rooftop of Prime Minister Shinzo Abe's office.
The radiation at the park is said to be unrelated to the 2011 Fukushima Disaster when a nuclear reactor was blown up by a tsunami and earthquake.
Janapese citizens frequently scan areas for radiation by themselves.