Japan's Fukushima prefecture began health checkups of 360,000 children amid worries that radiation from a crippled nuclear plant exposed them to the risk of thyroid abnormalities.

Many parents demanded the tests, drawing parallels with the 1986 Chernobyl nuclear disaster, after which locals reported thyroid disorders -- a problem sometimes associated with radiation exposure.

The screenings began after a recent unofficial survey reported that 10 out of 130 children evacuated from Fukushima had hormonal and other irregularities in the thyroid glands. The doctors who conducted the survey, however, said that they could not establish a link between the irregularities and the nuclear accident.

Officials said they would test some 360,000 children under the age of 18 and provide follow-up tests during their lifetimes.

The March 11 earthquake triggered a tsunami that tore into Japan's northeastern coast, leaving 20,000 people dead or missing and sparking meltdowns and explosions at the Fukushima nuclear power facility. It was the world's worst nuclear accident since Chernobyl.

Radiation fears are now a daily fact of life, with reported cases of contaminated water, beef, vegetables, tea and seafood due to the Fukushima crisis.