(Japantimes.co.jp) -- The government on Tuesday ordered a ban on the shipment of rice harvested in two more districts in Fukushima Prefecture, after tests detected dangerously high levels of radioactive cesium.

Chief Cabinet Secreatary Osamu Fujimura said the central government has instructed Fukushima Gov. Yuhei Sato to impose the ban on about 1,900 kg harvested in the Oguni district and 1,500 kg in the Tsukidate district, both in the city of Date.

On Monday, the Fukushima Prefectural Government announced that a combined 3,400 kg of unmilled rice harvested by two farms in the Oguni district and by one farm in the Tsukidate district contained between 580 and 1,050 becquerels per kilogram of radioactive cesium. The government's limit is 500 becquerels.

One of the farms in the Oguni district already has sold 9 kg of the tainted rice, the prefectural government said, adding it has yet to establish the identity of the buyer. The remainder of the Oguni rice has not reached the market, it said.

None of the rice harvested by the farm in Tsukidate has been distributed, and all 1,500 kg are currently being stored by the Japan Agricultural Cooperatives.

It is the second ban on rice grown in Fukushima Prefecture in the last two weeks. On Nov. 17, the government banned rice in the Onami district of the city of Fukushima after excessively high levels of cesium were detected.

The prefectural government also decided Tuesday to inspect rice harvested by about 2,300 farms in certain districts of the cities of Nihonmatsu and Motomiya where high radiation levels have been recorded.

Date is located next to the city of Fukushima, and parts of it have been designated as radiation hot spots where the annual exposure could exceed the maximum 20-millisievert limit.

"While we carried out the best inspection process we could think of, we must take the fact (that contaminated rice has been found) seriously," agriculture minister Michihiko Kano said after a Cabinet meeting, hinting it may be necessary to devise new processes for inspecting rice.

The government will do its best to identify the buyer of the contaminated Oguni rice, he said.

The tainted rice was detected in new tests the Fukushima Prefectural Government started conducting on rice harvested by about 1,500 farms in the cities of Fukushima and Date after the central government banned rice from the Onami district.

As of Monday, the tests had confirmed that rice from 10 farms in Onami contained excessive levels of cesium.

In October, Gov. Sato officially announced that test results for rice at 1,174 spots in the prefecture, including Date, confirmed that Fukushima's rice was not contaminated by radioactive materials and was safe to consume.

The initial inspections showed that 82 percent of the rice tested showed no traces of contamination, and the remaining samples contained radioactive cesium below the government-set limit.