Mid-air collisions in dogfights? Was this common?

[the330thbg]

Judging by what can, unfortunately occur at some airshows.., was this a fairly common happening in the skies over London during the blitz?

Any documentation on this?

Many thanks,

S.

Some examples below.
http://www.budgetfilms.com/clip/16070/

[the330thbg]

Bump

Bueller.., Bueller...., Bueller?

[Randy Haskin]

I'd say yes, absolutely. Probably not 'common', but I'd have to say that in the melees there had to have been some midairs just by the sheer volume of aircraft that were sharing the airspace.