Weird Activity (SP - Brazil)

Few days ago, unusual activities started to happen here in São Paulo (which is an state too where my city belongs) in many cities, some of them were reported by UFO magazine (www.ufo.com.br...).
Is known as Riolandia case, where massive UFOs were seen and few crop-circles appeared, well, they're not perfect crop circles of course but formations on sugar-canes are unusual, for sure.

Anyway, there's plenty material of this over the internet, check it out:

Video of the "formations": www.youtube.com...

INAPE report (translated by google)

First reports of the case (translated by google)

Returning to Riolândia to investigate (translated by google)

Bunch of information has been provided, few people claim to have video about the sightings, but unfortunately nothing was published so far.
So far so good, after a while researching UFOs and the Crop Circles phenomena I thought: "Well, this could be a prank, someone trying to get attention, etc".
But a few days ago it reached my town (Limeira) and the news was published today on the newspapers. People claim to have seen some UFOs zig-zagging around and think it's Extraterrestrial activity, while others are skeptical about it.
The first circle reports were made 3 days ago and those who made it claim the circles had perfect shape and the sugar-canes were not totally bended, well, see for yourself:

Photo 1

Photo 2

Photo 3

So, my point is, WTF is going on? Might be something usual for you living in the North Hemisphere, but it never happened here and the authorities are freaking out about this haha!
Anyway, I just wanted to share this with you and keep you alert because this is NOT normal.

If you have any questions just let me know, ok? See ya!

PS: Sorry for the bad words and messy english mods!