When making an arrest without a warrant, the officer shall inform the person to be arrested of the officer's authority and the cause of the arrest, unless:

1. The person to be arrested then is engaged in the commission of an offense;

2. Such person is pursued immediately after the commission of an offense or after an escape;

3. Such person flees or forcibly resists before the officer has opportunity so to inform the person; or

4. The giving of such information will imperil the arrest.