Custom Target sometimes work,sometime doesn't

This is my scenario

// on FragmentActivity Class
    Picasso picasso = Picasso.with(this);
    String[] imageUrls = {
            "http://digital-photography-school.com/wp-content/uploads/2013/03/Acorn256.png",
            "http://stereo-ssc.nascom.nasa.gov/beacon/latest_256/behind_euvi_195_latest.jpg",
            "http://littleblackapp.blob.core.windows.net/product3071/img10020_0.png" };

    private void initLoadImages() {
        for (int i = 0; i < imageUrls.length; i++) {
            String imageUrl = imageUrls[i];
            picasso.getSnapshot().dump();
            CustomTarget target = new CustomTarget(imageView, progressBar,
                    index);
            picasso.load(imageUrl).into(target);

        }

    }

    // this class is within the Activity class
    public class CustomTarget implements Target {
        public ImageView imageView;
        public ProgressBar progressBar;

        public CustomTarget(ImageView imageView, ProgressBar progressBar,
                int position) {
            this.imageView = imageView;
            this.progressBar = progressBar;
        }

        @Override
        public void onBitmapLoaded(final Bitmap bitmap, LoadedFrom from) {
            Log.i("bitmap loaded", "bitmap loaded");
            imageView.setImageBitmap(bitmap);

        }

        @Override
        public void onBitmapFailed() {

        }

    }

The custom target for first image will be always called but for other images it will be sometimes called and sometimes doesn’t. Have I implemented it in wrong way or am I missing something. I have used latest Picasso along with okHttp 1.2.1.

[JakeWharton]

You need to hold a strong reference to targets yourself.

            CustomTarget target = new CustomTarget(imageView, progressBar,
                    index);
            picasso.load(imageUrl).into(target);

after this line target has nothing referencing it so it will be garbaged collected.

[laaptu]

@hakimrie : Thanks for mentioning. I have updated the variable index now