The explosion occurred at around 9:30 a.m. local time on Wednesday while students from the university's urban planning and environmental engineering department were conducting sewage treatment experiments in a laboratory building on campus, the fire department said in a Wednesday statement obtained by the South China Morning Post
The explosion sparked a fire that "caused the death of three students who participated in the experiment," the statement said, although the cause behind the explosion has not yet been determined. The identities of those killed in the fire have not yet been revealed as authorities are currently investigating the incident.
Video footage of the fire being shared online shows the large building enveloped in dark smoke. Eight fire crews were sent to put out the fire, SMCP reported.
A statement by Beijing Jiaotong University states that the fire was put out within an hour. The area around the building as been cordoned off as the investigation takes place.
The incident comes only a month after another laboratory explosion at the Nanjing University of Chinese Medicine in Taizhou, which injured a professor and several students.
In December 2015, a 32-year-old postgraduate student died after a hydrogen cylinder exploded during an experiment at Tsinghua University in Beijing.