Knife crime involving children usually hits the headlines because it's very unusual, but lots of you have told us that doesn't make it any less scary to hear about.
So we asked David Trickey, who's an expert in helping kids through traumatic experiences, for advice on what you can do if you're worried.
Should children be worried about knife crime?
Yes. Just as they should be worried about strangers, road traffic accidents, global warming etc.
Being a little bit worried about these things motivates us to do something about them - for example, looking before you cross the road, not getting into a car with a stranger - which makes the world a little safer.
Being so worried that you don't actually leave the house, or can't stop thinking about it, is unhelpful though.
If children are worried they should talk to trusted adults about it (family, teachers etc).
Is it OK to be scared of being stabbed?
It's safer to run from anyone with a knife
It's very helpful to be scared of being stabbed, IF
being scared makes you decide to give the mugger your phone rather than putting up a fight, or makes you avoid hanging out with kids who are carrying knives.
BUT, it's less helpful if being scared stops you leaving the house or stops you enjoying anything.
Why do you think some children carry knives?
Children carry knives for lots of different reasons - to protect themselves, to be part of their peer group, because they are afraid of others carrying knives or because they want to frighten others.
How big a role does pressure from friends play in making kids want to carry a knife?
Fitting in with your peer group is really important to all of us - I'm wearing clothes that my peer group approve of - and becomes even more important if your family don't feel that you belong to them.
Adolescence is also an important time when we begin to switch our allegiance from our family (if we had any with them in the first place) to our peers.
What can they do to resist peer pressure, especially from older kids?
They need to have thought through the reasons why they don't want to carry a knife so their logic will help them at the times that peer pressure is strongest.
They need to have made an active decision that the reasons for not carrying outweigh the reasons for carrying, including peer pressure.
They also need to be prepared to be rejected by the knife-carrying kids. (In the long run, those that stand up are often more respected than those that cave in, but the long run is kind of irrelevant when your mates are laughing at you. )
They could get support from adults, like their mentors, teachers or family, and they could try to find groups of friends that are equally not interested in carrying.
What can kids who say they don't feel safe without a weapon do?
Your knife could be used AGAINST you
If kids think that carrying a weapon makes them feel safe, then they need to think this through a bit more. It probably makes them less safe.
Carrying a knife identifies you as a potential target for other knife carriers.
It might make you less likely to actively avoid confrontations - if you haven't got a knife you're more likely to avoid those kids, or run away if cornered, which is probably safer.
Out of control
If you get into a confrontation with a kid with a knife, is pulling out your knife really going to make a happy ending more likely?
They might not intend to actually use it, but situations escalate very quickly and things get out of control, which when there is one or more very sharp implements around can be very dangerous.
That's adrenalin for you - really useful when we had to run away from dinosaurs, but there aren't so many of them around these days, and it's less helpful for making rational decisions.
Where can they get help?
There are other ways of avoiding knife conflicts.
Some of them simply involve avoiding not getting into certain situations, some involve talking your way out, and some involve physical self defence stuff.
A really good self defence course might help.