10 Milliemes 1971 - Sudan, Error???

I found 4 of the 10 milliemes 1971 coin with an extra line above the camel rider's head, all in the same position and and same shape. Is this an error?

Coin link:
https://en.numista.com/catalogue/pieces11543.html

Photos of the four coins (all different):




Normal Coin for comparison:

And a picture of the whole coin of one of 'em:


Regards.

die break?

Probably...

Interesting find ..

According to Dato: "yes, for me its a die error"