This is Chin Bamboo dance.The dancers dance among the bamboo poles which are constantly hitting each other. This dance is very difficult, requiring a very coordinated timing between the dancers and the bamboo holders. One wrong move and your ankle will be hit hard with a bamboo pole.
Bamboo dance is not unique only to Chin people. Karen (Kayin) people also has the similar kind of dance with different style. The bamboo dance from karen is more famous in Myanmar but the Chin Bamboo dance is relative unheard of. This was the first time I saw this dance during my visit to Hakha in 2007.