Detecting a collision on the child of the gameobject

Hi there,

I have a game object called Character with RigidBody2D and Box Collider2D attached to it. I've created a child of that object, called Axe, and attached a circle collider to it. alt text

Problem is that in script that handles the enemies, whenever I want to check if the collision between axe and enemy appeared nothing happens.

Here is a code I use in EnemyController to detect collision with that child:

 void OnCollisionEnter2D(Collision2D col)
     {
         if (col.gameObject.CompareTag("Axe"))
         {
             EnemyAnim.SetBool("PlayerCollider", true);
             Instantiate(blood, rb2D.transform.position, Quaternion.identity);
             Destroy(gameObject);
         }
     }

Any tips how to dectect a collision between child of character and enemy?

Thanks in advance!