Hijacking of Courier bakkie

2 Black men, one with a blue shirt and one with a red shirt walked suspiciously away from a courier bakkie. The one with the red shirt waved his arms, indicating to their pick up vehicle to get them. I turned around and followed them. They drove a block away and stopped, where the one guy with the blue shirt got out, but as I approached and took pictures he went back to the passenger seat. The pick up vehicle is a municipal white bakkie. There must be at least 3 occupants inside.