This is also called a citizen’s arrest. Any ordinary person can arrest you, without a warrant of arrest, in these cases:

• If you committed a serious offence, or the person suspects that you committed a serious offence
• If the person is reasonably sure that you committed an offence and you try to run away when he or she tries to arrest you
• If you are fighting and someone may be seriously injured
• If the person thinks you went into any fenced land, or a kraal shed or stable, intending to steal crops or animals
• If the person finds you with some animals or crops which he or she suspects that you stole, and you can’t explain why you have them
• If the person is in charge of premises, or is the owner, he or she can arrest anyone who commits an offence on the premises

You are also an ‘ordinary person’. You can arrest other people in the above cases too. For example, someone snatches your bag in the street. You chase after them and catch them. You can lawfully arrest the person.