The Tokyo metropolitan government warned Wednesday that infants should not drink tap water as radioactive iodine exceeding the limit for them was detected in water at a purification plant, according to Kyodo.

According to the metropolitan government, 210 becquerels of radioactive iodine were detected per 1 kilogram of water against the limit of 100 becquerels.

The detection follows the 9.0 magnitude earthquake that hit Japan on March 11 that crippled Tokyo Electric Power Co.'s Fukushima Daiichi nuclear power plant, where radioactive materials have been leaked out.