I know ばか literally means "stupid/idiot" but i remember a scene when i was re-watching naruto. the context is:
"sarutobi asuma just got news that his close skilled friend (old comrade of him) was killed by akatsuki, he was very shocked and could not believe such a very strong, skilled friend was killed easily by akatsuki and then he said 'ばかな! bla bla bla'." i am sorry i can't fully provide what he said because my limited japanese skill.
I dont know equivalent of that word in english in the context above, maybe " huh, how can?". correct me if i am wrong.
so when is 'ばかな' used other than to insult people? and is it okay to say it to close friend (older) as expression?