A person breaks someone's mandible in alleged fight. Police can:

Ans is 'b' i.e. Arrest without warrant Fracture or dislocation of mandible is a 'Grievous Injury' for which punishment is defined under IPC 325. It's a 'cognizable offence' hence a police officer can arrest the accused without warrant.A cognizable offence is one where a police officer can arrest without warrant.A non-cognizable offence is one where police officer cannot arrest without warrant.Arrest is a tool in the hands of a police officer to prevent the accused from escaping the clutches of law. It helps the police officer to prevent further commission of offence as a precautionary method. A warrant is a written order issued by a Magistrate to a police officer commanding him to arrest a person. In most serious crimes there may not be sufficient time to obtain a warrant from the Magistrate. By the time police officer obtains warrant the accused may escape. So the necessity to obtain warrant is not required in serious crimes. In Cognizable offences, the person can be arrested without warrant while it is not possible in non-cognizable offences.