It was after dinner time as i was sitting on the couch watching tv and by chance i looked out of my first floor window(big window) to see two flashing objects in the sky. there is some construction space next to the place of residence, a park and more buildings . the two flashing lights were hovering above this space and then disappeared behind the buildings after about 10 seconds. my mother joked it was ufos. i didn't take her seriously. less than15 seconds later i see three more lights just floating and moving one behind the other. they eventually take like a turn and disappear behind the building. i was initially creeped out as no one else seemed to notice this and the streets and parks were quite active. then eventually i just wanted it to come back so i could find out what it was. i also researched to see if there are any scientific labs near my residence (to find another explanation) but didnt succeeded.