Is it a UFO or a natural phenomenon?
The mysterious activity in the clouds is a natural phenomenon. Ice crystals aligning to an electrical field generated by the cloud.
Electrical potential is generated within cloud. As the electrical field grows and moves, ice crystals align along the field and move with it, changing how they refract and reflect sunlight to the observer.
Note: The original footage is filmed in Singapore on Aug 15, 2011.
Witness Abrigatti: I was pool side in my apartment in Singapore, when I saw something weird in the skies. As I looked over head I saw some weird cloud shoots of light and puff as the clouds seemed to reform sporadically. I could see that a storm cloud was building, but the light and visual show was intriguing me.
Below the original video.