The allegations, in a BBC television programme, come a day after the chief legal adviser to the British province provoked outrage by suggesting an amnesty on crimes committed during the so-called Troubles.
During the early 1970s members of the British army's military reaction force carried out undercover patrols of west Belfast, then the heartland of the paramilitary group the Irish Republican Army (IRA).
Several members of the force described to the BBC how they were required to act "like a terror group" and some said they would shoot their "targets" even if they were unarmed.
They reportedly spoke out because they believe their role in the fight against the IRA has not been sufficiently recognised.
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The IRA, which wanted Northern Ireland to join its southern neighbour, finally gave up its fight in 2005.
The ministry of defence said all its soldiers had been required to act within the law, and said it would cooperate with any police investigation that arose from the revelations.
Sinn Fein President Gerry Adams, whose party was the political wing of the IRA, said the revelations emphasised the need for a truth and reconciliation process in Northern Ireland.
"The existence of the military reaction force and its activities have been known for many years but tonight's programme contains new information and provides a fresh insight into the use by the British government of counter-gangs and secret military units."
The programme is being broadcast the day after Attorney General John Larkin, who advises the devolved administration in Belfast, called for an end to prosecutions for offences committed before the 1998 peace accords.
His proposal was immediately condemned by relatives of victims on both sides, rights groups and British Prime Minister David Cameron, who said there would be no amnesty.
The Good Friday peace agreement led to a power-sharing government between the two sides, but community tensions remain and sporadic violence continues.