A319 First Officer reported the wing walkers and automated parking system indicated that the gate area was clear but a belt loader was parked in the safety zone. The belt loader was moved; but a bus then drove right in front. Afterwards; as the flight crew began to taxi in; a baggage cart drove under the aircraft's nose and the First Officer told the Captain to stop the aircraft.

Narrative

Parking at gate in ZZZ. As we turned in; both wing walkers and the park system said the gate area was clear and directed us in. We saw a belt loader parked completely inside the safety area on the right side of the gate area. We stopped the jet and directed the Right Wing Walker to move the belt loader. They acknowledged the loader; then raised their wand again and signaled us to keep coming in. This happened twice. Finally; they got the point that we weren't going to move until the safety zone was completely clear. It doesn't matter if the wing would have cleared it or not; it wasn't in a special safety box like many fuel pumps are.Then; as they were moving it; one crew bus decided to ignore the remaining Wing Walker who was standing near the service road stopping traffic; and the bus drove right in front of us. Our second Wing Walker returned; the Captain released the brake; and began to increase thrust to taxi in. Out of the corner of my eye; I noticed the bag cart with several carts that had been stopped on the Captain's side ignored the wing walkers and our forward movement; and drove under the aircraft's nose. I told the Captain to stop the plane and almost stomped on the brakes. That tug was so close; they completely disappeared from our vision for several seconds until they came out on my side.