The Iraqi army has recaptured the city of Mosul from Islamic State.
Prime Minister Haider al-Abadi announced "victory" and went to the city to congratulate the soldiers.
As the Iraqi soldiers made it to the centre of the city Islamic State militants threw themselves into the River Tigris, trying to flee the battlefield.
A US-trained elite Iraqi force in the Old City of Mosul reached the Tigris riverside, state TV said, indicating that the insurgents' last redoubt is on the verge of falling.
The battle for Mosul took eight months and ruined parts of the city, killing thousands of civilians and displacing nearly one million people.
Plumes of smoke rose over the Old City today and the decaying corpses of Islamic State fighters lay in the streets. Scattered bursts of gunfire could be heard and several airstrikes were carried out.
Iraqi military spokesman, Brigadier General Yahya Rasool, told state TV 30 militants had been killed attempting to get away by swimming across the Tigris.
Later, Iraqiya News ran and on-screen headline saying: 'Forces from the Counter Terrorism Service raised the Iraqi flag on the Tigris river bank in the Old City of Mosul."
Islamic State vowed yesterday to "fight to the death" in Mosul.
Cornered in a shrinking area of the city, the militants resorted to sending women suicide bombers among the thousands of civilians who are emerging from the battlefield wounded, malnourished and fearful.
The battle has also exacted a heavy toll on Iraq's security forces.
The Iraqi government does not reveal casualty figures, but a funding request from the US Department of Defense said the Counterterrorism Service, which has spearheaded the fight in Mosul, had suffered 40 percent losses.
The United States leads an international coalition that is backing the campaign against Islamic State in Mosul by conducting airstrikes against the militants and assisting troops on the ground.
The Department of Defense has requested $1.269 billion in U.S. budget funds for 2018 to continue supporting Iraqi forces.
Without Mosul - by far the largest city to fall under militant control - Islamic State's dominion in Iraq will be reduced to mainly rural, desert areas west and south of the city where tens of thousands of people live.
It is almost exactly three years since the ultra-hardline group's leader Abu Bakr al-Baghdadi proclaimed a "caliphate" spanning Syria and Iraq from the pulpit of the medieval Grand al-Nuri mosque.
Prime Minister Haider al-Abadi declared the end of Islamic State's "state of falsehood" a week ago, after security forces retook the mosque - although only after retreating militants blew it up.
The United Nations predicts it will cost more than $1 billion to repair basic infrastructure in Mosul. In some of the worst-affected areas, almost no buildings appear to have escaped damage and Mosul's dense construction means the extent of the devastation might be underestimated, U.N. officials said.
The militants are expected to revert to insurgent tactics as they lose territory.
The fall of Mosul also exposes ethnic and sectarian fractures between Arabs and Kurds over disputed territories or between Sunnis and the Shi’ite majority that have plagued Iraq for more than a decade.