DOHA (Reuters) - An influential group of Islamic scholars has denounced the forced expulsion of Christians from northern Iraq by Islamist hardliners, saying it paves the way for fighting between the country's ethnic and religious groups.

The Christian community of Mosul fled to the Kurdish autonomous region last week, ending a presence stretching back nearly 2,000 years, after Islamic State militants set them a deadline to submit to their rule or leave. [ID:nL6N0PU0DK]

"The International Union of Muslim Scholars (IUMS) condemns the forced expulsion of the Christian brothers of Iraq from their homes, cities and provinces," the group said in a statement posted on the website of its leader, the influential cleric Sheikh Youssef al-Qaradawi on Tuesday.

"These are acts that violate Islamic laws, Islamic conscience and leave but a negative image of Islam and Muslims."

The IUMS, comprising senior Sunni religious scholars from around the world with links to more moderate factions of the Muslim Brotherhood, views the Islamic State, which has taken control of a swathe of northern Iraq, as being too extreme and says its doctrine contradicts the true teachings of Islam.

It has rejected the Islamic State's declaration of a caliphate in Iraq and Syria as illegal under Muslim law, saying such a development can only be made after enough legitimate representatives of Muslim peoples have pledged their allegiance.

The Islamic State, an al Qaeda offshoot, relayed its ultimatum from mosque loudspeakers and spray painted Christian properties with the letter "N" for Nasrani, or Christian, residents said.

Fleeing Christians described being stopped by gunmen on the outskirts of Mosul and robbed of the goods they carried, suggesting the militants were implementing an order to Christians to leave behind all possessions.

The IUMS urged the Islamic State to allow Christians to return to their homes, saying the forced expulsion amounts to "spreading discord", a serious crime in traditional Muslim law.

"They (Christians) are native sons of Iraq and not intruders," it said. "The aim must be to bury discord, unite the ranks and solve Iraq's problems, rather than thrusting it into matters that would further complicate the situation," it added.

(Reporting by Sami Aboudi; Editing by Alison Williams)