By Maher Chmaytelli
BAGHDAD (Reuters) - Iraq's top Shi'ite Muslim cleric urged government and allied Shi'ite militia forces fighting to retake Falluja from Islamic State militants to spare trapped civilians amid reports of a budding humanitarian crisis in the city.
Grand Ayatollah Ali al-Sistani's appeal reflected concerns that a large civilian death toll in the battle for the mainly Sunni Muslim city could kindle increased sectarian strife in Iraq. The Baghdad government has been led by Shi'ites since the 2003 fall of Saddam Hussein, a member of the Sunni minority.
Sistani added his voice to many calls for restraint in the battle begun on Monday to retake Falluja, on Baghdad's western approaches and the first Iraqi city to fall under the control of the ultra-hardline Islamic State (IS), in January 2014.
"Sayyid Sistani reaffirms his recommendations that the ethics of jihad (Islamic holy war or struggle) be respected," his representative, Sheikh Abdul Mahdi al-Karbalai, said in a statement.
"Don't be extreme ... don't be treacherous. Don't kill an old man, nor a boy, nor a woman. Don't cut a tree unless you have to," he said, citing sayings of the Prophet Mohammed.
Aid agencies have become alarmed about civilian suffering in a city that has been under siege for six months, and the United Nations has urged combatants to protect inhabitants trying to escape the fighting.
APPEAL FOR CIVILIANS' SAFE PASSAGE
"Markets have exhausted food supplies and medicine is running out, leaving sick children and the elderly at particular risk," Save the Children aid agency said in a statement.
It said severe shortages had driven the price of a single can of infant milk up to $50 at times, making it unaffordable for the parents of thousands of children.
On Wednesday, Iraqi troops concentrated artillery fire on Falluja's northern and southern neighborhoods, according to a resident contacted via the Internet.
A Falluja hospital source said the overall death toll since Monday's launch of the government offensive had risen to 43 - 26 civilians and 17 militants.
"Fierce fighting is now raging around the city," Save the Children's statement said, reporting that only 700 people including 400 children had managed to escape as of Tuesday.
Up to 100,000 people have remained in the city, according to U.S. and Iraqi government estimates. Save the Children said up to 50,000 were being prevented from leaving Falluja.
The offensive is part of a government campaign to roll back Islamic State's seizure of wide tracts of northern and western Iraq. Baghdad's forces retook Ramadi, the Anbar provincial capital near Falluja, in December but have not yet tackled a bigger challenge - IS-held Mosul, Iraq's largest northern city.
An Iraqi military spokesman said troops were trying to tighten the encirclement of Falluja by advancing on the western front, near the village of Khalidiya.
An Islamic State statement reported by the Amaq news agency said Iraqi forces had been unable to advance on the southern front, near Amiriyat Falluja.
The Association of Muslim Scholars of Iraq, a hardline political organization formed after Saddam's ouster to represent Sunnis, has condemned the assault on Falluja as "an unjust aggression, a reflection of the vengeful spirit that the forces of evil harbor against this city".
Sistani wields enormous influence over Iraq's Shi'ites. It was at his call that Shi'ite militias regrouped in 2014 in a coalition known as Hashid Shaabi (Popular Mobilisation), to stem Islamic State's stunning advance through the north and west.
Hashid Shaabi will take part in encircling Falluja but will not enter the city unless the Iraqi army fails in doing so, said Hadi al-Amiri, the leader of the Badr Organisation, the largest component of the Shi'ite coalition.
(Addtional reporting by Saif Hameed; Editing by Mark Heinrich)