Which Government Agency Is Responsible For Vehicle Adverts Licencing?

Please I created this thread because I want to know the government agency that is responsible for the control and licensing of adverts that is placed on vehicles.

By adverts I mean the adverts that is placed on taxi roof tops with a cone-like plastic. And also the big stickers that is placed at the back of most Keke Napep and buses.

Any help will be so much appreciated. https://ift.tt/eA8V8J