The location where they are driving can be seen here:
In Google maps:
As can be seen, they drive INTO the city, towards the center where the SBU building is that they occupy.
We don't know if there might be vehicles before the first one that we see, but this column consists of (at least) the following vehicles (with Vostok battalion logo's):
#1 APC or BTR with infantry
#2 Truck with infantry
#3 White bus full of infantry
#4 small white truck (with supplies/ammo?)
#5 yellow bus with infantry
# green personal car with some soldiers
#7 grey van with anti-aircraft gun behind it
#8 ambulance with sirens and lights on
There are at least 80 people here.
It is clear that these are fresh troops from across the Russian border, because up till now they did not have an anti-aircraft gun like this.
Also notice how they use an ambulance to transport their troops... These people don't care about ethics.
See the interactive map of Donetsk fro more positions and events.
Read more about notorious Vostok battalion here.