Who is protected by the "principle of non-refoulement"?

Non-refoulement is a fundamental principle of international law that forbids a country receiving asylum seekers from returning them to a country in which they would be in likely danger of persecution based on "race, religion, nationality, membership of a particular social group or political opinion". Unlike political asylum, which applies to those who can prove a well-grounded fear of persecution based on certain category of persons, non-refoulement refers to the generic repatriation of people, including refugees into war zones and other disaster locales.