Corrected entry: After the explosion - I think the first one - the terrorists are going around killing the security men and taking their weapons - with one security man down and his gun on the floor, there is a yellow marker under his gun, we see the marker when the gun is taken. Maybe the yellow marker is there as a position marker, so the actor knows where to put his gun after he has been "killed" and fallen down. (00:31:50)
kh1616
17th Jun 2014
Correction: The 'marker' actually looks like it is a metal plate with screws attached to the floor itself. So I don't think it is a marker at all.