The suspected killer on the 14-year-old boy was a German citizen with a Kazakh passport. Over 70% of people in Kazakhstan are Muslims.
A pupil at secondary school near the German city of Dortmund has been killed by a fellow classmate, according to police.
Reports say a 15-year-old student stabbed a 14-year-old boy.
The attack happened at around 08:00 local time (07:00 GMT) at the Käthe Kollwitz comprehensive school in the town of Lünen.
From CIW NEWS Contributor
Germany crime immigration
Dortmund, North Rhine-Westphalia, Germany
Germany (DE) is estimated to have a population of 82.2 million with a growth rate during 2010-2015 of 0.1% pa.
At the same rate of change, in five years' time its population will increase by 0.4 million.
However, the rate has been much higher since 2015 when two million immigrants entered Germany (1.14 million net).