Unity 5 - Shoot up, enemy ship does not shoot

The enemy ship simply can not shoot and walk at the same time, or it does one thing or another.

    public class EnemyScript : MonoBehaviour {

    public float speed = 5f;


    // Use this for initialization
    void Start () {

    }

    // Update is called once per frame
    void Update () {

        Vector2 min = Camera.main.ViewportToWorldPoint(new Vector2(0,0));

        transform.Translate (new Vector3(0,1,0) * speed* Time.deltaTime);

        if (transform.position.y < min.y) {
            Destroy(gameObject);
        }
    }
}



    ublic class EnemyGunScript : MonoBehaviour {

    public GameObject HitL;
    public GameObject HitR;
    public GameObject EnemyBullet;
    public float nextFire = 1f;

    // Use this for initialization
    void Start () {

    }

    // Update is called once per frame
    void Update () {
        Invoke("FireEnemyBullet", 1f);
    }

    void FireEnemyBullet(){

        GameObject playerShip = GameObject.Find ("Player");

        if (playerShip != null && Time.time*3 >= nextFire) {

            GameObject bullet01 = (GameObject)Instantiate (EnemyBullet);
            bullet01.transform.position = HitL.transform.position;

            GameObject bullet02 = (GameObject)Instantiate (EnemyBullet);
            bullet02.transform.position = HitR.transform.position;

            //Vector2 direction = playerShip.transform.position - bullet.transform.position;

            //bullet01.GetComponent<EnemyBullet>().SetDirection(direction);

            //nextFire += Time.time/3;

            nextFire += 1.5f;

        } 

    }


}

I created a GameObject called gun and inside it I created two more hitR and hitL q is where the shots exit, the EnemyGunScript script is in gun and gun in the enemy ship. Please help me if you know a possible solution in javascript tmb serves.