XI'AN -- A swarm of bees has stung around 140 high school students and teachers in northwest China's Shaanxi Province, education authorities said Wednesday.

Some 80 people, including 76 students, were hospitalized after they were attacked at around 7:10 a.m. Tuesday near Hongshan High School in Qianyang County, said Lan Huiqiang, head of the county education and sports bureau.

Three students are still being treated in hospital, with one of them in a serious but not life threatening condition, Lan said.

A nest was later found under a bridge near the school and was removed. Safety checks were made in areas surrounding schools and kindergartens to prevent similar situations.