"Get out of this town or face a massacre."

It was a warning like no other. While Islamist extremists have distinguished themselves for their savagery, this particular warning did not come from them.

The threat came from a Christian group, called the Christian Mobilization militia, which is part of the Shia-dominated Popular Mobilization Forces paramilitary organisation, based in the northern Assyrian town of Tel Keppe in northern Iraq, the Middle East Monitor (MEMO) reported.

Moreover, the warning issued last week was addressed to Sunni Arab tribesmen who live in the town. They were given 72 hours to get out or else face annihilation.

Salman Esso Habba, the head of the Christian militia, claimed that the town of Tel Keppe belongs only to Christians. He said Christian homes and rights could no longer be usurped by the Sunnis, who he claimed occupied the town following the U.S.-led invasion of Iraq that ousted President Saddam Hussein in 2003.

For his warning and territorial claims, Habba drew the condemnation of Sabah Al-Mukhtar, a legal expert and head of the U.K.-based Arab Lawyers Network. Al-Mukhtar said Habba is actually threatening to commit genocide against the Sunnis, which he said is "disgraceful."

"He is threatening [the Sunni tribes] not because of what they have done, but because of who they are. That is the definition of genocide from a legal perspective," Al-Mukhtar told MEMO.

He warned that the threat, once carried out, would backfire on the Christians because they are still the minority in the area.

Christian Assyrian communities have already repudiated Christian militias in the region, saying their actions could threaten future peaceful coexistence with other religious communities in Iraq.

Last year, Patriarch Mar Luis Rafael, head of the Patriarchate of the Chaldean Church, issued a statement, saying they have "no near or far relations with the Babylonian Brigades [a Christian militia] or any other armed Christian factions."

The threat from the Christian militia came about three months after representatives from a number of Assyrian, Chaldean and Syriac political parties agreed to unite their military forces to fight the Islamic State.

In their joint statement released last November, the parties vowed to keep the Nineveh Plain free from conflicts, noting that the region and its inhabitants have already suffered enough as a result of these conflicts.

The agreement reportedly marked the first step to unify all Christian forces under one leadership.