The Iraqi army on Sunday resumed operations against ISIL in Mosul after a one-day pause, amid growing concerns over an escalating civilian death toll as fierce fighting spreads to the city's most densely populated areas.

The offensive was briefly put on hold after local officials and residents in west Mosul said suspected US-led coalition air raids last week had killed scores of civilians at the ISIL-held al-Jadida district.

Security forces on Saturday did not permit journalists to get to where the strikes were said to have taken place, but the coalition admitted that it had struck the area on March 17, and said it was investigating the reports of civilian deaths.

Details about what exactly happened on March 17 are difficult to confirm as Iraqi forces battle with Islamic State of Iraq and the Levant (ISIL) fighters to recapture the heavily populated parts of the western half of Mosul, the armed group's last stronghold in Iraq.

Witnesses and local officials said that more than 200 bodies were pulled from a collapsed building after a coalition air raid.

But in a statement on Sunday, the Iraqi army said there was no sign that the destroyed structure had been hit by a strike - blaming its collapse on booby traps set by ISIL instead.

"A team of military experts from field commanders checked the building where the media reported that the house was completely destroyed. All walls were booby-trapped and there is no hole that indicates an air strike," it said, adding that 61 bodies were recovered from the rubble.

READ MORE: Grief and questions amid wreckage of Mosul air strikes

Al Jazeera's Hoda Abdel-Hamid, reporting from a hospital in Erbil, northern Iraq, spoke to people who confirmed that they had lost family members in the air raids of March 17.

"We've been speaking to some of the patients and certainly the words air strikes come up a lot in the conversation," she said, referring to a man who said 22 of his relatives had been killed in an air raid, while he had to spend several days under the rubble before being rescued.

"When you ask them what happened … people here say the main problem is that you have ISIL fighters who are roaming around, going in and out of houses, on top of rooftops to take positions and then disappearing.

"So apparently many of the air strikes, according to the people we spoke here, hit the wrong target - simply by the time the air strike arrives and is called in, the ISIL fighters have disappeared."

'Brutal fighting'

The US-backed offensive to drive ISIL out of Mosul, now in its sixth month, has recaptured most of the city.

The Iraqi government announced that eastern Mosul had been recaptured from ISIL in January, but residents still report almost daily fighting in some areas.

Iraqi security and medical sources on Sunday said a t least 16 civilians, including two children, were killed by ISIL shelling in a popular marketplace in eastern Mosul.

Another 43 civilians were wounded in the attack, according to the sources.

In western Mosul, the Iraqi army's advances have stuttered in the past two weeks as fighting enters the narrow alleys of the Old City, home to the al-Nuri Mosque where ISIL group's leader Abu Bakr al-Baghdadi declared a caliphate spanning large areas of Iraq and Syria in 2014.

Iraqi forces on Sunday deployed snipers to target ISIL fighters who were using civilians as human shields, Joint Operations Command spokesman Brigadier General Yahya Rasool told the AFP news agency.

The military was relying on "light and medium weapons, among them sniper [rifles], to hunt for Daesh [ISIL] members" located among civilians, he said.

READ MORE: Battle for Mosul - Civilians at 'grave risk'

Rasool accused ISIL of gathering civilians together and then blowing up explosives-rigged vehicles nearby to make it look like "Iraqi forces ... are targeting innocent civilians".

However, Iraqi forces have also frequently fired mortar rounds and unguided rockets during the battle for west Mosul - weapons that pose a much greater risk to residents of areas where fighting is taking place.

Hundreds of thousands of civilians are still inside the Old City and are exposed to the intense fighting.

"Patients here say there is nowhere safe in western Mosul for civilians," Al Jazeera's Abdel-Hamid, reporting from the hospital in Erbil, said.

"They say the fight in western Mosul is not the same as the fight that happened in the east part of the city. They say it's much more brutal, with many more air strikes and much more shelling."

According to Iraqi authorities, more than 200,000 people have fled west Mosul since the operation to retake the area was launched on February 19.



But the United Nations has said that about 600,000 are still present inside the city.

Caroline Gluck, a senior public information officer in Iraq with the UN's refugee agency, said the situation is deteriorating daily.

"The fighting is coming closer to people's homes. It's a very densely packed area, particularly in the Old City, so families have been terrified by the mortars, the shelling and the air strikes," she told Al Jazeera from Baghdad.

Gluck said a major factor in many residents' "very difficult decision" to flee is growing hunger.

"Families have told us they rely on one meal a day - and that meal is really just water and flour. People are getting desperate; there is no fuel, no heating, and they are burning furniture and old rugs to try and stay warm."