Human shield
Human shield is a military term describing the use of civilians to deter an enemy from targeting one's military units. International law considers the use of human shields a war crime.
It may also be used to describe the use of civilians to literally shield soldiers during attacks, by forcing the civilians to march in front of the soldiers during human wave attacks. Of course the civilian casualty rate is extremely high and use of this technique is generally frowned upon. There were some instances of this in the Soviet Union during WWII.
The tactic was used by the Bosnian Serbs in 1994 and by Iraq in 1990.
These civilians may involuntarily be put in this position, or be anti-war activists, going voluntarily to target areas for this purpose, as in 2003 to Iraq.