Inserting a Model Property into an Img Element URL in Ember

I have a Model with an image_id property. I have a View for that Model that contains an image element. I need to insert the id into the image element's src property to complete the URL of the image so that I'm effectively doing this:

<img src="news + newsItem.imageID + .jpg"></img> 

My first attempt used a Handlebars helper:

<img src="news{{newsImageURL newsItem.imageID}}.jpg"></img> 

But this also inserted Metamprph script tags around it:

<img url="&lt;script id='metamorph-10-start' type='text/x-placeholder'&gt;&lt;/script&gt;news/7.jpg&lt;script id='metamorph-10-end' type='text/x-placeholder'&gt;&lt;/script&gt;" alt="" class="content-image news-media" /></a>

So I've looked at using bindAttr, however as I need to transform the image_id value(by prepending and appending the rest of the path), this doesn't seem like a solution either.