The United Arab Emirates has secretly paid hundreds of Colombian mercenaries to go fight in the civil war in Yemen on behalf of the Saudi Arabia-led coalition, the New York Times reported Wednesday.

The U.A.E. has reportedly deployed some 450 Latin American mercenary troops to Yemen – including Panamanian, Salvadoran and Chilean soldiers – to fight against Shi'ite Houthi rebels.

The Colombian troops are part of a 1,800 man brigade the U.A.E. has been training at an Emirati military base, which has been training secretly in the U.A.E. for five years. The mercenary program was once reportedly ran by Blackwater founder Erik Prince, but has since been run by the Emirati military.

They do not seem yet to have gone into combat, but they will be joining hundreds of Sudanese soldiers Saudi Arabia has hired to fight there - and possibly Eritrean troops too, the Times reported.

The Houthis, who have received military and financial support from Iran, have been reported recently as hiring their own African mercenaries, including from countries such as Ethiopia, to fight on their side.

A number of wealthy Middle Eastern countries seem to be outsourcing part of their military and security needs - and have been for years - but these troops have been mostly used until now for internal security and guarding purposes, and are only now being sent into combat.