KUNMING?-?Forty-two children remained hospitalized Tuesday after food poisoning sickened more than 300 students on Monday in a rural primary school in southwest China's Yunnan province, authorities said.

According to the government of Zhenxiong county, 337 children of the county's Dingla Primary School were admitted to the county hospital after eating lunch at school, with dozens showing symptoms of vomiting, diarrhea and fever.

By Tuesday morning, 247 checked out from the hospital and the rest 90 remained hospitalized. Another 48 students were able to check out from the hospital by 6 pm Tuesday, leaving the rest 42 hospitalized.

Authorities have ordered the primary school to suspend serving lunch, and an investigation into suspected food poisoning is underway.