Lately a lot of UFO sightings in the Netherlands are caused by Thai airballoons.
The so called Kong Ming lampions or Khom Loy, are rice paper objects with a 80 cm diameter, mostly orange colored. The balloons can fly up to 500 m
high and stay in the air at least 30 minutes.
Used in the early days for communicating during war they are used today for spiritual use (sending away the evil spirits)
They sell them on the internet as Ufoballon.
Altough I'm a believer, keep in mind that when you see multiple orange objects floating in the air it can be one of these ricepaper objects.