High levels of radioactive substances have been detected in seawater near the Fukushima Number One nuclear power plant in Japan.

Tokyo Electric Power Company, the plant’s operator, said Tuesday that the level of iodine-131 was 126 times higher and caesium-134 was nearly 25 times higher than government-set standards.

The company announced the figure after analyzing seawater that was sampled about 100 meters from the plant’s waterway at 2:30 p.m Monday.

The company said the radioactive substances are likely to have poured into the sea due to the spraying of water on the plant’s reactors number three and four and due to the rain.

The electric firm was quick to add, however, that the amount of detected substances has had no immediate effects on the human body. The firm also said that it is too early to assess the impact the substances would have on marine products.