reporter: certainly there are multiple motives going on with these attacks. many attacks like this on civilians happen without breaking through into the international news. but the tragedy is more than 1 million people in burkina faso alone in the last two years have had to flee their homes. that area, that border region, is largely ungovernable. and an attack of this scale does sometimes indicate that this is a group of militants that are doing a reprisal attack. many of these villages have gotten together vigilante groups, anti-islamic defense or anti-jihadi, i should say, defense groups. so it has the hallmarks of that kind of response where a large number of people are tragically killed in what is often a reprisal attack. now several years ago, these militants were generally attacked, military outposts, u.n. blue helmet outposts,