Property security guards fight with people during office hours, and the other party starts first, and then I fight back, and the other party is injured.

This is best discussed in private. Although they made the mistake first, you also participated, and as a result, both sides of the police station ended badly. You can ask powerful police or arbitration institutions to intervene to help the public security bureau, and as a result, you have to accompany them to pay for medical expenses. It's disgraceful that the other party has suffered a little more than you. You can go to the public security bureau if you have money.