More than 3,000 primary school students in Haicheng suffered from poisoning after they drank soya milk produced by a Sino-US joint venture on March 19.

Sources at the Ministry of Health urged local health officials to step up their inquiries into the incident.

"Such a grave case should have been reported immediately," the Beijing Times quoted an unnamed health official.

According to Ministry of Health regulations, major poisoning incidents and suspected cases that involve over 100 people or take place in schools should be reported to the ministry within six hours.

The notice also said those who try to cover up such incidents will also be punished.

Meanwhile, sources said the Ministry of Education has started an investigation and said the results will be released as soon as possible.

According to a parent, surnamed Yang, who took his child to Beijing for medical treatment, representatives of around 80 parents went to the ministry to ask for help.

The cause of the poisoning is still unknown.

Sources with the area's two major hospitals, Haicheng Zhongxin Hospital and 626 Hospital, who treated the affected students, said they could not disclose the cause of the poisoning to parents and media because this was a matter for the authorities.

But the municipal government of Anshan, which covers Haicheng, remained silent.

It is reported that the Anshan Baorun Milk Company, the producer of the suspect soya milk, has been closed down by local quality and technical supervision authorities for further investigations.

(China Daily April 10, 2003)