Sixty-two migrant workers who suffered food poisoning after eating at a Shanghai construction site cafeteria were sickened by food contaminated by bacteria, the city's food and drug agency said Tuesday.

The Shanghai food and drug watchdog analyzed food at the cafeteria at the construction site of the Shanghai Xinwei commerce and trade plaza after receiving reports that more than 60 workers were ill on Tuesday, and found that chicken and pork might be the source of the poisoning.

The workers were hospitalized after eating at the cafeteria on Monday evening. They developed cramps and diarrhea and were taken to hospital on Tuesday morning after being diagnosed with food poisoning.

All the workers have been discharged after receiving treatment at the hospital.

The cafeteria has been closed and the exact cause of the incident is still under investigation.

The incident follows two other mass poisonings this month.

On Monday, 19 middle-school students were hospitalized with suspected food poisoning after eating lunch in a school cafeteria in Changchun, capital of northeast China's Jilin Province.

On April 9, more than 200 people fell ill and one person died in Harbin in northeastern China after they ate a hospital breakfast suspected of being contaminated with rat poison.

(Xinhua News Agency April 18, 2007)