UFO observed by Mirage pilots 2004

Summary

In October 2004, a leader of a Mirage 4 patrol in France was alerted by his colleague about an object following them since 5 a.m. The leader also managed to spot the object, which disappeared within 15 to 20 seconds. Although initially thought to be a fighter jet, air traffic controllers did not detect any trace of the object. The case remains unexplained.