BEIJING (AP) — Two people were killed and at least nine others were injured in a laboratory explosion at a university in eastern China, state media said Monday.

The blast occurred Sunday afternoon at the Nanjing University of Aeronautics and Astronautics. Nanjing is a major center of higher education that attracts large numbers of foreign students. Officials were investigating the cause of the explosion at the university’s School of Materials Science and Technology, state broadcaster CCTV reported.

The identities of the victims have not been released. The school’s website says more than 1,000 foreign students have attended courses at the school in engineering, business and the Chinese language. But it wasn’t clear how many remained after China began imposing pandemic travel restrictions.

China has sought to establish itself as a major player in global aviation and spaceflight, although it’s efforts to produce commercial jetliners have yet to make a significant impact.