Since Guatamala is on the southern Mexican border, they have a similar situation to the one the US has with Mex.
What I've heard though, is that the Mexicans simply kill the Guatamalans. I've no source and I'd like to know how close to the truth that is?
Mexico has long had issues with Guatemalan guerrillas on it's southern border. This borders Chiapas were Mexico has it's own insurgency-refugee problems.
Been a fair amount of bloodshed over the decades.
http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB100/index2.htm