Source: Islamic State video threatens attacks in Russia 'very soon'
Example:
In this this file photo released on May 4, 2015, on a militant website, which has been verified and is consistent with other AP reporting, Islamic State militants pass by a convoy in Tel Abyad, northeast Syria.
The verb pass obviously is trying to say that the Islamic militants are passing past the cameraman who's taping them or any other point on the road for that matter. But how exactly do you understand pass by a convoy? A convoy is usually a group of anything that's military and moving. Everything makes total sense to me here except for the use of the preposition by. So, what exactly does pass or move by a convoy mean?
The picture in question (copied from the website for your convenience):