The savages let loose, or the cruel fate of the loyalists

1783 image rom the British Museum who say;
Description
American loyalists are being murdered by Red Indians. An Indian (left) seizes by the hair a loyalist lying on the ground, and holds up a knife saying "I'll scalp him". Another Indian (right) raises a tomahawk in both hands above a loyalist who kneels on one knee, saying "O cruel Fate! is this the Return for our Loyalty". The Indian says, "I'll tomahawk the Dog".
A third Indian (left) pulls a rope attached to the ropes by which four loyalists hang by the neck to the branch of a tree, inscribed "Recommended to Congress by lord S------e" [Shelburne]. He is saying "I have them all in a String."
The Indians all wear tall feather head-dresses and kilts of feathers. Of the six loyalists, two of those hanging from the tree are dressed as military officers, the others as civilians.
Beneath the design is engraved:

"Is this a Peace, when Loyalists must bleed?
It is a Bloody Piece of work indeed."c. March 1783