More than 120 people in Iraqi city killed in past week of heavy fighting, some allegedly in coalition air attacks.

The US-led coalition in Iraq is investigating allegations that air attacks have killed civilians in the battle for western Mosul that has intensified over the past week.

Al Jazeera’s sources say more than 120 civilians have been killed as Iraqi forces – backed by coalition air power – move to take the remaining vestiges of the city that are held by the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group. About 200,000 people remain trapped by the heavy fighting.

“The coalition is aware of allegations of civilian casualties,” said a statement from the press office of Operation Inherent Resolve that was emailed to Al Jazeera.

“The coalition and the Iraqi security forces are making every attempt to safeguard civilians as they liberate the city from ISIS terrorists who are using snipers to target civilians trying to flee the city… The coalition takes all allegations of civilian casualties seriously and will assess these allegations.”

The statement added the results of the assessment will be published in a monthly civilian casualty report.

READ MORE: Iraqi troops push for last ISIL holdouts in Mosul

The battle to recapture the last stronghold of ISIL in Iraq has now entered its eighth month.

Iraqi government forces, backed by US advisers, artillery and air support, have cleared east and most of western Mosul and are now focused on controlling the Old City.

Iraqi civilians have paid a heavy price as fighting rages on.

“We moved out and got frightened by heavy air attacks,” one civilian who escaped the fighting in western Mosul told Al Jazeera. “We fled after our house was destroyed by mortar shelling.”

The close-quarter fighting has intensified with reports that ISIL fighters have gathered at the historic al-Nuri Mosque – a centuries-old structure famous for its leaning minaret – to make a last stand as Iraqi forces encircle the armed group in its de facto capital since it captured the city in 2014.

“As we entered Zinjili neighbourhood, we inflicted heavy losses on ISIL. We have destroyed many car bombs and houses rigged with explosives while evacuating many civilians to safety,” Brigadier-General Mahdi Abbas told Al Jazeera.

Nearly 200,000 civilians are caught in an area of about eight square kilometres.

Al Jazeera’s Osama bin Javaid, reporting from Erbil just east of Mosul, said observers are urging the Iraqi military and US-led coalition to take care of civilians, despite the intensity of combat against ISIL.

“Saving people is proving to be easier said than done,” Javaid said. “Aid workers and rights groups have been repeating their concerns that in the process to push ISIL out, Iraqi forces must make sure that civilians are not caught in the crossfire.”