Iraqi Prime Minister Al-Abadi declares victory over ISIS in Mosul Mosul had been under ISIS control since the summer of 2014.

 -- Iraqi Prime Minister Haider al-Abadi has declared victory in Mosul over ISIS, roughly three years after the group took control over the city and about nine months after his country launched an operation to retake the area.

Troops from Iraqi Special Forces marked the victory by planting the Iraqi flag on the bank of the Tigris River.

Al-Abadi first proclaimed victory on Twitter, and released a photo of himself shaking hands with an officer in Iraq's military shortly after having touched down there.

"PM Al-Abadi arrives in Mosul to announce its liberation and congratulate the armed forces and Iraqi people on this victory," a description of the photo said.

Officials appear to be in concert regarding the much anticipated declaration:

Lt. Gen. Jassim Nizal of the army's 9th Division also announced that his forces achieved "victory" in their sector, prior to the arrival of Al-Abadi. A similar announcement was made by the militarized Federal Police, according to a report by the Associated Press.

His soldiers danced to patriotic music atop tanks even as airstrikes sent plumes of smoke into the air nearby, the AP reported.

ISIS beaten, but not gone

Iraq launched the operation to retake Mosul from ISIS in October, and the group is now limited to a small swath of territory on which they are still using human shields and suicide bombers as self-defense, the AP reported today.

ISIS holdouts in western Iraq and Syria, as well as a number of other countries, may continue to attack and bomb targets in the city after Sunday's declaration of victory, according to ABC News' analysis.

Meanwhile, fighting goes on in the Syrian city of Raqqa, the de-facto capital of the ISIS caliphate.

The U.S.-trained, equipped and backed Syrian Democratic Forces (SDF) have entered Raqqa from a number of sides. The group, mostly composed of members of a group known as the People’s Protection Units (YPG), is a mix of Arabs and Kurds.

The YPG has been fighting ISIS for years, and is now considered a battle-hardened opponent.

Based solely on Raqqa’s physical makeup, defeating ISIS there will likely be easier to accomplish than it was in Mosul, according to ABC News' analysis, and there is far less terrain to cover in the city.

A humanitarian crisis goes on

For now, the ongoing humanitarian crisis is affecting the survivors of both the fighting and occupation that took place in Mosul.

Many Mosul residents are traumatized, and the scene bears similarities to what happened to Dresden at the end of World War II, when allied forces ousted the Nazis from Germany, according to ABC News' reporters on the ground.

ISIS fighters sometimes charge improbable rates for necessities, or the equivalent of $6 for a bottle of water and $80 for a package of crackers, an escapee from the city told ABC News last week.

Over 897,000 people have been displaced by the fighting in Mosul, according to a report by the AP.

ABC News' Ian Pannell and The Associated Press contributed to this report.