Twenty-seven students of a primary school in Hebei Province were receiving medical treatment Tuesday after a suspected food poisoning incident, local authorities said.

Fifteen children were being treated at the Intensive Cure Unit in the People's Hospital of Yutian County in the city of Tangshan, said sources with the hospital.

The sick children are from the county's Yuying Primary School, a private boarding school with over 800 students.

Several students had been vomiting and were suffering from fevers and diarrhea on Thursday, while more children became sick from Sunday night to Tuesday morning, said a spokesman with the county's education bureau.

He said samples of the school's food and drinking water were being examined and medical workers had disinfected the dining hall there.

In a similar case in Hebei's Longhua County, 135 students were sickened after drinking contaminated water at Zhangjiying Middle School.

As of Tuesday, 50 students were still under medical observation, but all were in a stable condition, the government of Longhua County said in a press release.