Weird UFO caught over Iași, Romania

On February 25, 2016, two persons were in the city of Iași (largest city in eastern Romania) when they have seen and photographed a very impressive UFO flying over buildings. What is it?

Witness report:

1. I was with my friend at Palas Mall Iasi Romania taking night photos of Palas Mall using my Samsung S4 mobile phone.

2. I thought I saw a bright whitish shining object moving in a zig zag manner over my camera screen, so I decided to take a few more shots of the same spots.

3. I thought it could be an UFO.

4. It moves over the camera screen in a zig zag manner at high speed and disappeared suddenly.

5. I am not sure what I saw was for real.

6. I don't know. All I knew was of the few photos taken of the same direction of the sky, only one of the photos have a blue disc with white light above the building.