Splitted mkv files

Hello,


How do I join splitted mkv files? I downloaded movies from the internet. The files format is

xxx.mkv.001, xxx.mkv.002, xxx.mkv.003........... How do I join them together? I used

Hj-split but it didnt join them.... it just join the first part. the other part cannot be joined

together or play. Only the first part can be played and joined.

How do I join them all into 1 file?