A fascinating NYT piece on the Colombian mercenaries, from the UAE, being deployed to the Yemen. although not for combat yet. They join others too:
The arrival in Yemen of 450 Latin American troops — among them are also Panamanian, Salvadoran and Chilean soldiers.....They join hundreds of Sudanese soldiers whom Saudi Arabia has recruited to fight there as part of the coalition......a recent United Nations report cited claims that some 400 Eritrean troops might be embedded with the Emirati soldiers in Yemen — something that, if true, could violate a United Nations resolution restricting Eritrean military activities.
Link:http://www.nytimes.com/2015/11/26/world/middleeast/emirates-secretly-sends-colombian-mercenaries-to-fight-in-yemen.html?