Who were the Galileans whose blood Pilate mingled with their sacrifices?

The passage from the Gospel of Luke 13 has a very curious beginning. We hear about an episode involving Pontius Pilate that is not recounted in any of the other Gospels. It says Pontius Pilate had mingled the blood of some Galileans with their sacrifices. (Luke 13:1-5). > **Luke 13:1-5** > > **New International Version (NIV)** > > 13 Now there were some present at that time who told Jesus about the > Galileans whose blood Pilate had mixed with their sacrifices. 2 Jesus > answered, “Do you think that these Galileans were worse sinners than > all the other Galileans because they suffered this way? 3 I tell you, > no! But unless you repent, you too will all perish. 4 Or those > eighteen who died when the tower in Siloam fell on them—do you think > they were more guilty than all the others living in Jerusalem? 5 I > tell you, no! But unless you repent, you too will all perish. ’” Who were the galileans whose blood Pilate mingled with their sacrifices? There's some historical/tradition information? Any clue?