Iraqi security forces backed by U.S.-led coalition airstrikes and in collaboration with Kurdish Peshmerga troops and a Christian militia have besieged the Iraqi Christian town of Qaraqosh as part of the offensive to liberate the nearby city of Mosul from the Islamic State (ISIS/ISIL), reports CNN.

The news network did not identify the Christian paramilitary group fighting to liberate Qaraqosh, which lies about 10 miles away from Mosul, a city that was “once considered the heartland of Iraq’s Christian population,” reports Christian Today.

Nevertheless, the non-denominational Christian news outlet adds that Nineveh Plain Forces (NPF), one of several Christian militias operating in Iraq, are participating in the operation to free Mosul and the surrounding areas.

Moreover, the Assyrian Confederation of Europe (ACE) has noted that the Iraqi Christian militia known as the Nineveh Plain Protection Units (NPU) has been “tasked” with participating in the military campaign to liberate the Assyria Nineveh Plain, the historical homeland of the Assyrian Christians, and “is officially recognized and supported by the Iraqi government.”

Mosul is the second largest city in Iraq and the capital of Nineveh province, home to the largest concentration of Christians and other ethno-religious minorities in Iraq. The Assyria Nineveh Plain region is located in the province.

Qaraqosh, also in Nineveh province, was once home to Iraq’s largest Christian community, considered one of the oldest in the world.

In a statement released Monday, the day that the Mosul offensive began, the NPF said:

We salute the [Kurdish] Peshmerga forces, all Iraqi military forces, the federal police and the international coalition on the launch of the operations that will allow the retaking of the province of Nineveh.

The NPF noted that it represents the “Chaldean-Syriac-Assyrian” people of Iraq, adding that it is “honored to participate in these operations to liberate all of our occupied territories, and to push out the terrorist gangs of ISIS.”

“We have sworn to fight relentlessly, side by side with the allied forces, in order to free all of our cities and villages in the Nineveh Plain and Mosul area,” continued the NPF statement.

CNN learned from a Christian militia general that the U.S.-backed forces fighting on behalf of the Iraqi government “are facing fierce resistance and exchanging heavy gunfire with militants” in Qaraqosh, adding:

Iraqi security forces, Peshmerga fighters and a Christian paramilitary group have forced ISIS fighters into the center of Qaraqosh, where airstrikes are pounding the militants, in apparent coalition support of the assault, Gen. Amr Shamoun from the Christian militia group said.

It’s the latest clash with ISIS militants in the coalition’s aggressive push toward Mosul aimed at unshackling the strategic city from the terror group’s brutal control.

The operation has been complicated since ISIS apparently brought civilians into Qaraqosh, which was abandoned after militants took over in 2014.

Part of Qaraqosh has already been liberated, Shamoun said.

News that U.S.-backed forces were trying to recapture the Christian town from ISIS sparked jubilation among the Christians who were forced to flee the town, many of whom have made the city of Irbil, the capital of Iraqi Kurdistan, their home.

CNN notes:

They [Christians in Erbil] held a vigil overnight, holding candles and singing hymns, images showed, while others gathered in the street, cheering and dancing.

But their celebrations may have come too soon. ISIS appeared to be putting up a real fight in Qaraqosh, as the terror group has in several areas since the operation launched Monday.

There is disagreement among the Christian community in Iraq.

Some Christians would prefer to fight to liberate Nineveh province independent of the Kurdish Peshmerga troops.

Members of the Christian and Yezidi minority groups have accused the Kurds of stealing their land and of abandoning them when ISIS stormed their territory back in 2014.

ISIS jihadists have committed genocide against the Christian community and other ethno-religious minorities in Iraq. As a result, the number of Christians in Iraq has plummeted.

Participating in the offensive to take back Mosul is a coalition of up to 30,000 Iraqi government forces, Kurdish Peshmerga troops, Sunni Arab tribesman, and Iran-allied Shiite militias, all advised by American troops and backed by U.S.-led airstrikes

ISIS has an estimated 3,000 to 5,000 jihadists fighting to defend the Mosul.

Meanwhile, more than 5,000 U.S. forces have been deployed to Iraq.