CHANGSHA - Over 100 high school students have fallen ill after eating street food in Central China's Hunan province, and one of them is in a severe condition, local authorities said Tuesday.

They suffered dry mouthes, vomiting and skin redness on Sunday afternoon after eating bean jelly and cold noodles at a snack food stand outside the No 2 High School of Longhui county, according to a county government spokesman.

The students then went to local hospitals for medical checkups. By 1 pm on Tuesday, 110 had returned to school, but five were still being treated, including one in a severe condition, the spokesman said.

Local disease control authorities found nitrite in food sold at the stand and accordingly concluded it was a food poisoning case, he said.

One of the eatery's owners, surnamed Zhang, was detained by police on Monday on suspicion of putting dangerous articles into food.

Police are hunting the other owner, who fled, the spokesman added.