Movie about ethnic massacre where hero played by famous African-American actor protects people in a big house [closed]

Way back in Year (class) 8 (6 years ago) I watched a movie during what I remember was either Religious Education or English Language way back in 2011. The movie however seemed to be 10 years older like it seemed like a movie from the 2000s (it was in colour).

The language spoken was definitely English because I remember the hero of the movie was an African-American actor who was pretty famous at the time. Thinking now the movie reminds me of the purge but much more older and set in a country like Africa or South America).

Anyway here are the key facts I know/think I know about this movie:

• There is a massacre that happens due to an assassination
• The people leading the massacre suspects certain groups of people in their country/community to do it
• Before the massacre happens a friend of the hero (I think he becomes the main protagonist near the end) is caught harboring weapons (mostly cheap butcher knives I think) and he tips off to the hero that there will be a massacre and that his family should move country.
• The massacre starts off slow, at the start a few houses are set on fire and the hero starts to worry.
• Local police and soldiers (probably corrupt) don't intervene with these people who go round house to house killing certain types of people
• I think that the hero of the movie doesn't have to worry because either he is friends with the leaders of the rebels or are not those who are persecuted by these soldiers and rogue civilians
• The hero believes what these people are doing is wrong and harbors people in his mansion/shelter (a building of importance because I remember white soldiers protected the place)
• Eventually the soldiers leave and what happens next is the hero meets the person mentioned before who has a sex dungeon full of slaves and on the way there the hero sees loads of dead bodies on the side walk
• I believe that the hero said to the people inside the shelter that if the hero does not return that they should suicide? or something like that
• The rest is hazy but I believe what happens is like special operatives come and save them by clearing an area that used to be controlled by the people committing the massacre
• The main bit I know is that the point of this massacre is ethnic cleansing or to make some kind of statement.

The teacher had it on DVD so I don't know what time the movie was showing in cinemas.

Appearances of the characters: I don't know much about this other than that 90 percent of the characters other than the soldiers protecting the mansion were African or African-American.