BAGHDAD – Hundreds of Iraqi soldiers were killed and more than 3,000 wounded during the five-week battle to recapture Fallujah from the Islamic State (IS) group, Middle East Eye can reveal.

Since the beginning of Iraq's war against IS in June 2014, when almost a third of the country's territory was seized after the dramatic collapse of the Iraqi army, officials have either refused to comment or downplayed the numbers of casualties among Iraqi security forces.

General Hadi Erzaje, deputy of the Fallujah military operations commander, previously told MEE: "We have casualties, but not that many. We are involved in fighting so we cannot reveal such information.”

But a senior security official speaking on condition of anonymity told MEE that at least 394 members of the security forces were killed and 3,308 wounded in the battle, which started on 23 May and ended earlier this month.

Medical and other military sources put the death toll even higher, telling MEE this week that more than 900 soldiers were killed in the battle.

These numbers do not include members of militias slain while fighting in Fallujah. Nor have Iraqi officials released figures for deaths of Fallujah residents. More than 80,000 residents are estimated to have been displaced during the fighting.

The same sources said that 35,000 Iraqi forces, backed by multi-sect paramilitary troops and the US-led international coalition against IS, killed thousands of militants during the offensive.

The recapture of the city represents a "devastating blow" to the organisation, analysts and military officers told MEE.

A US military official told the Military Times on Thursday that the true size of IS’s fighting force was in question after Fallujah.

For at least the second time in recent weeks, Iraqi Prime Minister Haider al-Abadi on Sunday announced the liberation of Fallujah and raised the Iraqi flag on government buildings in the city centre.

But until now, it has been unclear what the cost of the campaign has been for Iraqis.

'A nuclear bomb'

Most of the security forces who died in Fallujah were killed either by suicide car bombs or rocket attacks used by the militants on a wide scale towards the end of the battle to block the advancing forces, sources said.

The Iraqi Counter-Terrorism Squad, an elite fighting unit, had the lowest number of deaths. The highest casualties, military sources said, were among federal police troops who fought without air cover in the northern region of Fallujah and also secured the city centre.

"We are not army or counter-terrorism services, we are federal police… We do not have tanks or jets. We were fighting in our flesh," General Lieutenant Ra'ad Jawdat, the commander of Iraqi federal police, told MEE.

Jawdat said federal police operating in the city’s northern hub were attacked by 90 suicide car bombs.

"If we put them together, their impact would be equal to a nuclear bomb," he said.

Jawdat would not comment on how many police died in Fallujah.

Militant casualties

Fallujah - which is also called the City of Mosques after the hundreds of places of worship built in the era of Saddam Hussein, who encouraged Sunni Muslim merchants to build the religious establishments tax-free - had been the base of most of IS’s senior commanders in Iraq and Syria.

Some experts say its capture may mark the beginning of the end for IS in Iraq, although the group still controls the key northern city of Mosul.

"Fallujah was the brain of the insect,” Hisham al-Hashimi, an Iraqi expert on armed Islamic groups and a governmental security adviser, told MEE.

Hashimi and most Iraqi officials that MEE spoke with say that Fallujah was the weak flank of Baghdad, Babel, Karbala, Najaf, Ssalahuddin and Anbar provinces and was used as a launching pad for most suicide attacks that targeted these provinces over the past decade.

Iraqi military sources told MEE that at least 2,500 IS fighters were killed in Fallujah and its suburbs. Another 2,186 were arrested by Iraqi forces trying to flee the city among displaced families.

"They [IS militants] left the city with the fleeing families. Some of them used fake IDs, others were disguised in women’s clothing," General Erzaje told MEE.

The number of arrested militants may increase because Iraqi security authorities are still screening the records of another 6,000 detainees held by local security authorities in temporary detention sites near Fallujah, Erzaje said.

The number of casualties on both sides is also expected to increase as current figures do not include those deemed missing or the bodies of soldiers and militants still in the city, the sources said.

Despite the losses, some analysts said the recapture of Fallujah should be seen as a triumph that has raised the morale of Iraqi forces.

"Fallujah was the dynamo of the organisation. Whoever won the battle in Fallujah, won the war," Hashimi said.

"Now, we can say Daesh [IS] lost the war. When it lost Fallujah, it lost the war in Iraq.”

This article is available in French on Middle East Eye French edition.