The authorities in Guangdong's provincial capital promised to expand inspections of rice and related products after detecting eight batches of tainted rice and rice noodles.

The move aims to ensure only quality rice, rice noodles and related products are sold in the southern metropolis where the grain is a staple food, according to a statement on the Guangzhou Food and Drug Administration's website.

The administration launched an inspection campaign in recent weeks and found the cadmium content of six batches of rice and another two batches of rice noodles exceeded national standards.

"All the packages of tainted rice and rice noodles have now been sealed shut," said the statement that was published on Sunday.

The rice was purchased from neighboring Hunan province and the noodles were produced by two factories in Dongguan, a Pearl River delta city in Guangdong province.

Meanwhile, the cadmium content of rice from two local restaurants and the canteens of two universities was inspected and also found to exceed national standards, according to the statement.

No cadmium poisonings have been reported in Guangzhou, according to sources with the city's center of disease prevention and control.

Xie Jianfeng, director of the food service center from Zhongkai University of Agriculture and Engineering, said his university was a victim of the tainted rice case after it purchased 20 bags of Cuizhu brand rice noodles for breakfasts in March.

The noodles with excessive cadmium content were produced by a factory in Daojiao township in Dongguan, he said.

"The rice noodle manufacturer has a license to operate and its products meet the State's hygiene requirements but it has no provisions for cadmium content inspections," Xie told local media.

"The university has sealed up a remaining nine bags of rice noodles for further investigation," he added.

A senior executive from the rice noodle factory said his company was a victim of the tainted rice when it purchased 12 tons of the grain from Hunan province early this year.

"Now the company has sealed up the remaining suspected tainted rice noodles for further investigation and has promised to recall all the tainted products it has sold," he said.

Insiders said Cuizhu brand rice noodles used to sell well in Guangzhou and about 80 percent of the rice noodles sold in Guangzhou are produced by the rice companies in the Daojiao township of Dongguan.

Huang Weiliang, manager of the No 3 Canteen of South China Business College of Guangdong University of Foreign Studies, said no tainted rice has been cooked for the students and teachers.

The college received the tainted rice from a local supplier and eight bags of it were cooked for a test meal in March.

"We immediately sealed up the tainted rice, which came from Hunan province, when we learned the cadmium content of the rice inspected exceeded national standards," he said.

"Now the canteen uses rice purchased from Jiangxi province," he added.

Trade at the two restaurants suffered badly when news of the inspections was released.

An executive named Liang from Pacific Seafood Restaurant in Guangzhou said the tainted rice case has seriously affected her restaurant's business, which used to be brisk.

"Some long-standing customers of the restaurant have even come to ask for an explanation," Liang said.

Local experts said rice absorbs cadmium from polluted soil.