Also Avianca and Viva –this last one is a low cost–?

Not sure when in the process –someone will probably chip in with that answer– but what I do know is that they won't let you board when they find this and will charge you the price difference in the airport. Even if they don't catch you in the first segment, they have a warning during the purchase process that is quite clear: wherever/whenever you are caught –outbound or return leg– you will be assessed a $177 charge or will be denied boarding.

Update: i just tried to do a mock booking and when you input as ID type a passport number that is not peruvian (i tried with US), there is a warning: "the ticket you selected is only for residents. the day of your flight you will have to proof residency or a fine will be assessed to you". I think that is it, right?