Why did An Song detain the North Korean weapon DC8 in the movie Equator? What's his purpose?

Probably to give some warning to those underworld figures. He wants to solve this dangerous thing in Hong Kong and tell Equatorial Hong Kong that they are the boss, not their world.

Equator is an action film produced by All Asia Pictures 20 15. The film was directed by Lok Man Leung and Kim-ching Luk, and co-starred by Jacky Cheung, Nick Cheung, Wang Xueyin, Zhang zhen, Shawn Yue, Choi Siwon, Chi Zhenxi, Wen Yongshan and Feng Wenjuan.

The film tells the story of the joint efforts of Chinese and Korean military and police elites to resolve the super nuclear weapons crisis.

The film is scheduled to be released in China on April 30th, 20 15.