France's Louvre museum plans to send more than 20 artworks to Japan, including Fukushima prefecture, near the stricken nuclear plant, in order to show solidarity with the disaster-hit country.

The exhibition will run from April 20 to September 17 in Japan's Iwate, Miyagi and Fukushima prefectures, said Jean-Luc Martinez, director of the department of Greek, Etruscan and Roman Antiquities at the Louvre.

Experts from the International Atomic Energy Agency arrived in the Japanese city of Fukushima on Sunday to observe the massive decontamination effort following the world's worst nuclear disaster since Chernobyl.

Local doctors also began a long-term survey of children for thyroid abnormalities, a problem associated with radiation exposure. Officials hope to test some 360,000 people who were under the age of 18 when the nuclear crisis began in March, and then provide follow-ups throughout their lifetimes.

A strong 6.4-magnitude earthquake shook northeast Japan's Fukushima prefecture, home to a crippled nuclear power plant, early Sunday, but there was no risk of tsunami, seismologists said.

Local police said they had no immediate reports of casualties or major damage from the tremor which hit at 3:54am (18:54 GMT Saturday).

More than six times the legal limit of radioactive caesium has been found in beef from Fukushima prefecture, home to Japan's crippled nuclear plant, an official statement said Saturday.

The meat came from one of 11 cows shipped this month to Tokyo from a farmer in Minamisoma city, according to the statement by the Tokyo metropolitan government.

Japan plans to send more than 20,000 soldiers into its northern disaster zone Monday in an intensive mission to recover the bodies of those killed in last month's earthquake and tsunami.

More than 12,000 people are missing and presumed dead from the twin disasters that hit March 11. Some were likely swept out to sea, while others are buried under the mass of rubble. About 14,300 are confirmed dead.

Authorities may for the first time ban access to the evacuation zone around Japan's crippled nuclear plant, citing concerns Wednesday over radiation risks for residents who may be returning to check on their homes.

About 70,000-80,000 people were living in the 10 towns and villages within 12 miles (20 kilometers) of the Fukushima Dai-ichi plant, which has been leaking radiation after a March 11 earthquake and tsunami wrecked its power and cooling systems.

Traces of Iodine-131 from Japan’s nuclear plant were found on low-lying foliage in Lebanon although they don’t pose a danger to human health, said the National Council for Scientific Research.

The small findings have now been confirmed in samples of rainwater and soaked foliage by rain that fell between April 4 and 6, according to CNRS.