A Shanghai university has apologized after video spread online of campus security guards beating stray dogs inside a bag.

Video shot over the weekend shows the three guards carrying a sack of stray dogs through campus while ignoring questions from students. Next, they set the sack down on the lawn in front of the school’s library. One of the guards then picks up what appears to be a hammer and starts whacking the bag.

The dogs inside can be heard crying out in pain.

This happened at Shanghai Jian Qiao University, located out in the far reaches of Pudong. The school explained that it had hired the guards after receiving dozens of reports of stray dogs attacking students and teachers on campus with 32 injuries this semester.

However, school officials declared that the guards had obviously gone too far, saying that the security company had been asked to suspend those responsible.