What to do if your are assaulted for your bicycle or other possessions.
In the unlikely event that you are mugged for your bicycle or belongings, police recommend you give these up as you might otherwise risk injury as well as losing your bike. They are advising victims to call 999 immediately, especially if there is a possibility of catching the culprits. They have said not to be concerned about calling 999 with a non-life threatening incident - they have internal prioritizing procedures.
Obviously if you were calling after the event then 999 would no longer be appropriate and you should contact your local police station.
You can report incidents either by phone or in person. When you report the theft/assaut ask for your CAD' (Computer Aided Despatch) or 'CRIS' (Crime Reference Information System') number. Having a number will help you to trace the progress of your case.
If you have theft insurance you will need to report the theft to your insurance company or insurance broker, and provide them with a police crime number.