Release International, which supports persecuted Christians worldwide, said the military stepped up its campaign against the mainly Christian Kachin people in April.
They launched attacks using artillery, helicopter gunships and infantry. Troops have displaced thousands, driving them from their burning homes.
The military have also occupied churches and interrogated entire congregations.
There are reports that the soldiers are using rape as a weapon of war and are deliberately targeting camps for the displaced, which is a war crime. They are also said to be sowing landmines to make villages uninhabitable.
Andrew Boyd, spokesperson for the charity, told Premier the oppression amounts to war crimes.
"We're talking about something like 10,000 people displaced and what we saw happening with the Rohingya Muslims, all of the brutality of that, exactly the same kinds of tactics, we're now seeing happening with the largely Christian Kachin people," he said.
"People have been displaced. They've been moved from their homes to camps, they've been moved from one camp to another camp. If that's true, and the evidence certainly points in that direction, these are war crimes."
According to Release International, conflict between the controlling Myanmese people and other peoples erupted after World War Two. Some Christian tribes, who sided with the British against the Japanese, expected a homeland of their own in return. Instead they have faced 60 further years of conflict.
Christians make up around nine per cent of the population and have long been targets for religious persecution in Myanmar.
Release International said Buddhist monks have led violent attacks against churches and church leaders, house churches have been banned and there have been attempts to outlaw religious conversion. There have also been legal moves to enforce the notion that to be Burmese is to be Buddhist
Boyd added: "There is a very powerful movement within Burma to say that if you are Burmese, you must be a Buddhist. In fact there have been moves to try to enshrine that in law and prevent religious conversion there."
Release International is working with partners in Burma to support families impacted by persecution. Release is also supporting efforts by the International Christian Association to train Christians and supply Bibles - the authorities have outlawed Bibles translated into the languages of the indigenous tribes.
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