Thousands of disgruntled students smashed up their high school campus in the southwestern Chinese province of Guizhou in the early hours of Friday morning after an outbreak of food poisoning made hundreds of them sick.

Students at Guizhou’s Puding County No. 1 High School ran riot through their dormitories, smashing windows and prompting China’s ruling Communist Party county leaders to rush to the school to deal with the incident, the county government said in a statement on its website.

It said no one was hurt, but made no mention of the mass food poisoning incident, prompting a slew of critical comments on social media sites.

Social media posts said 3,000 students at the high school’s Hengshui campus near Guizhou’s Anshun city had also staged large-scale protests after more than 400 students became ill.

“Why were the students rioting? Because on Thursday night, the ambulances just kept coming to the campus all night,” one user wrote. “The ambulances came from the People’s Hospital, the Chinese Medicine Hospital and the Youhao Hospital.”

“How must the parents feel when they get to the campus and see their kids at death’s door?”

The tweet said protesting students were also angry over high fees and frequent use of out-of-date foods in the canteen.