The Iraqi Prime Minister has celebrated victory in Mosul with his 'brave forces' as details of ISIS atrocities in the final hours of its brutal rule continue to emerge.

Haider al-Abadi proclaimed the liberation of the city as a 'victory over darkness, brutality and terrorism' as he shared the moment with his troops and local people.

He said: 'I announce to the whole world today the end, failure and collapse of the mythical terrorist state.

'We joined the people of Mosul in their celebration of the city's liberation, brought about through the sacrifices of our brave forces.'

A 100,000-strong coalition of Iraqi government units, Kurdish Peshmerga fighters and Shi'ite militias launched the offensive to recapture the city ten months ago.

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Iraqi Prime Minister Haider al-Abadi (centre) posed for this photograph in Mosul after declaring victory against ISIS in the city

Video shows al-Abadi celebrating victory over 'brutality and terrorism' while dancing around with his troops and local people

He posted the clip on his personal Twitter account with the caption: 'We joined the people of Mosul in their celebration of the city's liberation'

Members of the Iraqi federal police forces celebrate in the Old City after the government declared victory

Government troops raised an Iraqi flag in the city to celebrate their victory while the Prime Minister called for a 'feast day'

Mr Abadi, wearing a black military uniform and flanked by his commanders, thanked troops and the coalition, which included US air support.

'We announce the total victory for Iraq and all Iraqis,' he said, speaking from a small base in western Mosul on the edge of the Old City.

'This great feast day crowned the victories of the fighters and the Iraqis for the past three years.'

But he warned that more challenges lay in the future, saying: 'We have another mission ahead of us, to create stability and to clear Daesh cells.

'That requires an intelligence and security effort, and the unity which enabled us to fight Daesh,' he said, using the Arabic acronym for the terror group.

The US-led coalition that backed the Mosul offensive and is supporting another assault on IS's Syrian bastion Raqqa hailed the victory.

However, Lieutenant General Stephen Townsend, the commander of the operation, warned work was still needed to defeat ISIS.

'This victory alone does not eliminate (IS) and there is still a tough fight ahead,' he said.

'But the loss of one of its twin capitals and a jewel of their so-called caliphate is a decisive blow.'

And US Secretary of State Rex Tillerson said: 'On behalf of President Trump and the American people, I congratulate Prime Minister Abadi and the Iraqi people.

'This is a critical milestone in the global fight against ISIS, and underscores the success of the international effort led by the Iraqi Security Forces.'

News of ISIS atrocities have been passed on by civilians who were trapped inside the devastated city during the ten month siege.

Faced with hundreds of fleeing people, fanatics executed seven children to try and stem the flow of refugees and even used their own relatives as human shields.

There were reports some fanatics resorted to leaping into the Tigris river in a bid to escape with total defeat looming.

ISIS terrorists were cornered in Mosul as Iraqi forces retook the strategic city in the north of the country

Al-Abadi proclaimed 'victory' over ISIS following a massive airstrike against the terrorists still holed up in the city

The Prime Minister yesterday visited a military base in western Mosul where he congratulated the Iraqi Forces and its civilian population after reportedly defeating ISIS jihadists

Terrorists in Mosul's Old City used their families - including women and children - as human shields.

TRUMP: ISLAMIC STATE IS DOOMED 'Today Iraqi security forces supported by the United States and the global coalition, liberated the city of Mosul from its longtime nightmare under the rule of ISIS. 'We congratulate Prime Minister Abadi, the Iraqi security forces and all the Iraqis for their victory over terrorists who are the enemies of all civilized people.' 'The victory in Mosul, a city where ISIS once proclaimed its so-called caliphate signals that its days in Iraq and Syria are numbered. We will continue to seek the total destruction of ISIS.' Advertisement

The bodies of the youngsters were then strapped to lampposts in the town of Tal Afar, according to local reports.

Despite the inroads, the United Nations says there is no end in sight to the humanitarian crisis in Iraq.

It said thousands of Mosul residents will likely remain displaced from the city because of 'extensive damage caused during the conflict.'

Airstrikes, artillery and militant bombings have destroyed thousands of buildings as well as key infrastructure in Mosul.

Iraq's Interior Ministry says more than half of all buildings in western Mosul, where the fighting was heaviest, were damaged or destroyed.

More than 800,000 people have been forced from their homes since the operation began in October.

Iraqi forces launched the operation to retake Mosul last October and began the weeks-long push through the Old City district in June.

Iraqis celebrate in Tahrir square while holding national flags as they wait for the final announcement of the defeat of the Islamic state militants, in Baghdad, Iraq

Iraqi people with tears in their eyes celebrate the liberation of the embattled city of Mosul in Baghdad, Iraq on July 9

How Islamic State has been pushed back in the battle for Mosul.

That victory comes at an enormous cost: much of Iraq's second city in ruins, thousands dead and wounded, and nearly a million people forced from their homes.

Enormous challenges lie ahead, not just in rebuilding Mosul but in tackling the continued presence elsewhere of ISIS.

AMNESTY: PROBE MOSUL WAR CRIMES In documenting the conflict between January and mid-May, Amnesty found IS violated international humanitarian law and committed war crimes. The jihadist group used civilians as 'human shields' and 'summarily killed hundreds, if not thousands' of people as they tried to flee, hanging victims' bodies in public places, Amnesty said. The human rights organisation also criticised Iraqi forces and the US-led coalition, stating they carried out 'a series of unlawful attacks' in the city. Pro-government forces used 'imprecise, explosive weapons' in the urban conflict and allegedly used disproportionate force, such as a March 17 attack cited by Amnesty in which 105 civilians died in an air strike targeting two IS snipers. Advertisement

Iraqi forces waved flags and flashed victory signs after Abadi arrived in the city.

'This victory is for all Iraqis, not just for us,' Mohanned Jassem, a member of the elite Counter-Terrorism Service, said at the police base where Abadi met commanders.

Mr Jassem, who fought in most of the other main battles of the war against IS, said Mosul was the toughest.

'I took part in fighting in Ramadi and Tikrit and Salaheddin and Baiji and Al-Qayyarah... but the fighting here in (ISIS's) stronghold was the most violent,' he said.

ISIS swept across much of Iraq's Sunni Arab heartland in a lightning offensive in mid-2014, proclaiming a 'caliphate' straddling Iraq and neighbouring Syria.

Imposing its brutal interpretation of Islamic law, the group committed widespread atrocities and organised or inspired deadly attacks in Iraq, Syria and abroad.

French President Emmanuel Macron was among the first world leaders to offer his congratulations.

'Mosul liberated from Daesh,' he tweeted. 'Homage from France to all those, with our troops, who contributed to this victory.'

This soldier held up two fingers to celebrate the success of the offensive against the Islamic State, which has held the city for the past three years

Joyous members of the Iraqi federal police celebrated in the Old City of Mosul after the country's government announced victory against the terrorists in Mosul

French President Emmanuel Macron praised the defeat of ISIS in the city which was assisted by his jets

British Defence Secretary Michael Fallon congratulated al-Abadi and the 'Iraqi forces who have been fighting on the ground with great bravery'.

The European Union called the victory 'a decisive step in the campaign to eliminate terrorist control in parts of Iraq'.

IS has lost most of the territory it once controlled, and the coalition is aiming to oust the jihadists from their Syrian stronghold Raqqa.

The city is under assault by US-backed Arab and Kurdish forces.

Iraqi forces launched their campaign to recapture Mosul in October, seizing its eastern side in January and launching the battle for its western part the next month.

But the fight grew tougher when security forces entered the densely populated Old City on the western bank of the Tigris River, which divides the city.

Even in the final days of the battle, thousands of civilians remained trapped inside the Old City and some of those who fled arrived grief-stricken after losing relatives in jihadist sniper fire and bombardments.

Iraqi Prime Minister Haider al-Abadi is pictured in Mosul, Iraq on July 9 as civilians wave flags and celebrate ISIS' defeat

The United Nations said Sunday that 920,000 civilians have fled their homes since the battle for Mosul began last autumn.

'It's a relief to know that the military campaign in Mosul is ending. The fighting may be over, but the humanitarian crisis is not,' Lise Grande, the UN's humanitarian coordinator in Iraq, said in a statement.

The recapture of Mosul will also not mark the end of the threat posed by IS, which controls territory elsewhere in Iraq and is able to carry out frequent bombings in government-held areas.

In Iraq it holds towns including Tal Afar and Hawijah in the north, as well as territory in western Anbar province.

It also continues to hold significant territory in Syria, including in Raqa, where the US-backed Syrian Democratic Forces (SDF) are battling to oust the jihadist group after penetrating its fortified historic centre.

While the loss of Mosul is a major blow to the jihadists, it is not a fatal one.

'We should not view the recapture of Mosul as the death knell for ISIS,' said Patrick Martin, Iraq analyst at the Institute for the Study of War.

'If security forces do not take steps to ensure that gains against IS are sustained for the long-term, then ISIS could theoretically resurge and recapture urban terrain,' he said.

Iraqi Prime Minister Haider al-Abadi is pictured with his arms aloft as he is surrounded by military personnel in Mosul, Iraq