ANSWER:

If they are fighting for Islam and to defend themselves and their families, they will be considered as martyr. However, if fighting would only make things worse for themselves and for other civilians, they must not do this as the harm far exceeds the benefits. 

Kindly refer to the following link(s):  

 

Sheikh,I live in …..,here in k….. I see many Muslim youngsters join some groups to fight against the army and the government since the army will either toucher them or kill their loved once.. now my qn is what if these guys join those groups to fight back n die during the fight. Will they attain martyrdom? Or they will have some other reward from Allah?