Removing Image links from category page but not post

I have a page that will show all posts from a certain category with a thumbnail on the post. I'm not using featured image for this image. I want to remove the link code so that the picture is not clickable on the category page. But I want the image in the actual post to be clickable so I can use lightbox. IS there any way to perform this action?

Hi!
Our themes do not support this function. Perhaps you can find a solution on the official site of WordPress http://wordpress.org/support/.