This could be acne scars.
You can use fresh lemon juice on them to fade them away. If you do, first try a patch test. Lemon juice can be drying too so use moisturiser afterwards
There are also lightning creams out there for uneven skin tone. Creams you should look out for should contain ingredients like Kojic acid, mulberry, licorice, and so on. For more info please visit this thread.
http://www.askmehelpdesk.com/skin-li...ns-190905.html