The US-backed coalition liberated more than 90 percent of the Syrian city of Raqqa, which was under the control of the Islamic State, the agencies said.
The UK-based Syrian Observatory for Human Rights said on Wednesday that the alliance had taken more than 90 percent of the city, adding that the major remaining hurdle for its forces was a large concentration of mines in the area.
IS has pulled out of the north of the city and abandoned its grain silos and mills.
Hundreds of thousands of people have been killed and millions more displaced since civil war broke out in Syria following protests against President Bashar al-Assad in March 2011.
"After hundreds of their fighters were killed in recent weeks, [those remaining] will not be able to resist much longer in Raqqa as their military equipment and basic necessities are dwindling", he said.
The SDF, a coalition made up of both Kurdish and Arab fighters, managed to encircle the city in June, when the full-scale offensive to oust the militants began.
According to him, the fighting was raging in six districts of the city, including the city center, where the government buildings are located, and around the Saat and Delle squares where ISIL terrorists publicly executed civilians.
In Deir ez-Zor province, where the SDF and Syrian army forces are running parallel, at time conflicting, campaigns against ISIS, the SDF reported they advanced five kilometres since Tuesday evening northeast of Deir ez-Zor city.
The remaining ISIL fighters in the city have almost run out of food and munitions, the Observatory reported. The cause of the fire is unknown.