Logic problem with RaycastHit and prefabs scripts

Hi! I have a game with a hero and enemies. The enemies are prefabs that, when hit by a bullet, drop boxes that I have do touch on to apply some heal to the hero's life.

The logic problem is that when I have some boxes on the scene, I touch one of them the heal value should be 5, but what happens is that for some reason this runs for the number of boxes I have on the scene. For example: the scene has 4 boxes, and when I touch one of them the value applied is 20, or 4 * 5.

It is finding all objects with the tag "pack" when I touch one of them... but why?

What could be wrong?

Here is my code:

using UnityEngine;

using System.Collections;

public class Package : MonoBehaviour {

public GraphicalInterface gui;

 cam = GameObject.Find("Camera").camera;
 gui = cam.GetComponent<GraphicalInterface>();

 foreach(Touch touch in Input.touches) {

     if(touch.phase == TouchPhase.Began) {

         Ray ray = cam.ScreenPointToRay(touch.position);
         RaycastHit hit;

         if(Physics.Raycast(ray, out hit) && hit.collider.gameObject.tag == "pack" && !gui.isGameOver) {

             gui.ApplyHeal(5);
             Destroy(hit.collider.gameObject);
         }
     }
 }

}

}