I had something similar happen somewhere in India (I forget where, but probably Mumbai or Delhi), except we were in a taxi!
My wife and I were in the back row, when the driver suddenly stopped, and a guy got in the front seat... and then 2 more got in the back, one at either side of us (which yes, was extremely uncomfortable). Nobody said a word the whole time. The driver drove off, and dropped all of them off a short time later.
Very strange!