On April 21st i was outside for a couple of minutes while at work. It was 3:30 pm. There was a clear blue sky, with some white clouds around the horizon, but it was very bright and sunny. I was looking up at the sky when i suddenly saw a white, round, short cigar shaped object moving slowly across the sky. It was in the northern direction, just above the top of a small mountain with some apartment blocks and houses on it, and slowly moving towards the top and disappeared behind it after about 15 seconds.Location was about 59���26'N 10���37'E.First i thought 'hey a plane!' because there hadn't been any air traffic for days because of the volcano in Iceland.From what i would guess is that it flew much lower then an airplane. A little bit slower too. It was a bright white tube with rounded edges. No wings, or marks or anything on it. It flew in a perfect straight line and held a very steady speed. Somehow there was something really calm about it. I don't know. I really concentrated on what i saw, and heard, but it didn't make a sound. There was no sound at all! Earlier today i had heard the first plane in days, and remembered that to listen for it when i saw the object, but it was completely silent. It's a very quiet neighborhood, so there wasn't much noise at all.I compared it to some birds as well, but it was too calm, the steady speed, and the straight line, no shaking or swinging.I thought of a balloon too, but a balloon would've been affected by the wind and it's direction and speed would vary.I've never seen a blimp here, and it was too small and had no propulsion of any kind as far as you could see.I would think that it's extremely unusual for me to see a UFO in the couple of minutes that i'm outside my work in this small town here in south Norway. There's nothing interesting or significant here. The chances are one in a billion i'd think... But still, it really made an impression on me and i really tried to find out what it could be while looking at it, but i really don't know what it is.