I was walking down Ivan Vazov street, and looked in the direction of the football field, it's a construction site at the moment for some large store. I looked at the sky and saw those lights, yellow-orange, pretty big (maybe 5-10 times bigger than the biggest star), slowly appearing and disappearing, as if the object was rotating, or just switching the lights on/off. I dont know if it was a single object with lights or multiple objects. Overall I observed about 4 cycles of the lights slowly appearing and slowly disappearing. At some point the object started moving slowly. I shot a video with my 5 megapixel phone camera. Then the light slowly faded and never appeared again. I waited for a couple of minutes and walked away.I immediately thought it is a UFO, as I've seen something similar in the area a few years ago (tho it was a single light of similar size and color), and my father has seen the same. I felt kind of calm and even disconnected while taking the video, but afterwards I felt pretty excited and a little scared. I was amazed and there were shivers running down my spine and trough my body.