Runway 34R Unusual Movement

[Grahame Hutchison]

I noticed two SACL vehicles on ADS-B, parked down at the threshold end of Runway 34R, nothing unusual, but when I checked visually there were also two
Mini-Buses. Two teams of workers, maybe 20 in total were walking line abreast across the grass area at the side of the Runway. They walked at right angles
to the Runway, and then along the Runway for some distance.

Did someone lose their wallet ?

Were they hunting Rabbits ?

Collecting FOD ?

Images taken from my balcony, 4km away.