19th November 2010. During the time of this filming, an Airforce Exercise was allegedly being carried out. According to the OP, there appears to be a triangular craft midway through the video. Is this part of the exercise and therefor could it be the (semi) Top Secret TR-3B Aurora/Astra, just regular aircraft or something else? 

Personally I couldn't detect the triangular nature of the craft whilst viewing the video, therefor I captured a series of screenshots after the alleged triangular craft showed up. The above image was captured from the video, blown up to 300% on the screen and then another 200% on photoshop. A triangular shape can just about be made from the image and I have drawn some crude lines on the second image to determine the possible shape of the craft. The image is from 04:57 on the video timeline.

Belgium in the early 1990's had a massive wave of ufo sightings all over the country, The belgium government finally came out and told the public about the issue and said about an incident where they scrambled belgium air force F16's to intercept one of these objects eventually one aircraft had a lock on to the object and then it zipped off out of sight at thousands of miles an hour, interesting stuff.

These three videos were captured in Santiago, Chile on December 17th 2010. Interestingly, on the same day of these sightings, the Chile Airforce carried out an operation in the skies above Santiago. People have suggested that this was a confusion tactic or to just simply debunk any more sightings as airforce craft, of course it's also very probable that they are just planes flying in formation.