Islamic terrorism threat in Mexico?

I found it really notable that outgoing head of the Mexican intelligence-counter espionage agency CISEN (created in the same year as CIA, whose function it resembles), Guillermo Valdés, who is being replaced by Alejandro Poiré, would say in his farewell statement that "we can not rule out the risk of an eventual presence of Islamic terrorism on our soil."

I cannot recall to ever have heard anything concrete regarding islamic terrorist threats in Mexico. If Valdés knows of something new, why did he not elaborate? And if there aren't any specific threats, why make this statement?