Is it rare In UK?

happened a couple times  by a terrorist ..just be alert when you are out no matter what country you are in as you now and then get mental fools  about ..stay in safe areas 

The truth is everywhere you go in the world there will be a very slight minority that will commit violent crimes through bad circumstance or behaviour, dont become a slave to your anxiety of leaving the house, although its hard to see in all forms of media the positivity in the world, I assure you there is much beauty, compassion, kindness, selflessness, bravery, courage and love that our kind show everyday, its just hard to see when you're clouding your vision in negative worry, like condensation on a window you will never see life clearly. 

So leave the house and look for beauty, see the way couples hold hands as they walk or parents playing with children, the old people feeding birds, the young love struggling to pick a card in the shop a person putting flowers on a grave showing care for those who are no longer with us.

The world has an abundance of love, go and receive it with all your senses.

Depends where you go.....

Places like London, Middlesbrough, Sheffield, Birmingham, Manchester, Leeds, Bradford, Liverpool, Glasgow, Cardiff, Swansea, Nottingham, Derby, Newcastle-upon-Tyne, etc have long held "a bit of a reputation" across the country for having to keep your wits about you.

Sleepier places like Whitby, Filey, Bowness-on-Windermere, Hornsea (east yorks) + the smaller rural parts across Norfolk, Lincolnshire + the Pennines are generally quieter and safer

no the British in the UK have been attacked from October 1939 it is only the Attackers that have changed from Nazis to IRA to Muslim terrorists and Rapists

I grew up in London I am London wise I won't go to Peckham Mile end Road Old Kent Road after dark and I will stay away from Scunthorpe

In Australia where I live, we don't have a Police station and virtually No Muslims and No Violence you do the Maths

There are some places on this planet that are less safe than others, the UK isn't one of them.  But as with any place, you need to be cautious, and maintain situational awareness.  It also helps to not get drunk in unfamiliar areas as that makes you a target. 

Yes, it's incredibly rare. 

Unless you live in specific areas which have gang issues (and are of an age where that might affect you)

Ok so where do you live? It makes a difference.

Where you live is what matters. If you are white and live in Peckham or Tower Hamlets a night a time stroll my invite trouble. In most other areas violence is uncommon.