Damascus: The Syrian Democratic Forces (SDF) have captured 80 per cent of Tabqa city from the Islamic State militant group, an SDF spokesman said.
The advance on Monday came as part of the offensive against the IS in Raqqa province, the de facto capital of IS, Xinhua news agency reported.
The Syrian Observatory for Human Rights said the forces, a rebel group led by Kurdish fighters and backed by the US, captured most of Tabqa in Raqqa countryside except two neighbourhoods close to Euphrates, the largest dam in Syria.
Talal Silo, the SDF military spokesman, said there were three neighbourhoods under the IS control in Tabqa and the Euphrates Dam and that the operation will strip the IS from them and the dam.
The observatory, which relies on a network of activists on ground, said negotiations were underway for the evacuation of the remaining IS militants from Tabqa towards Raqqa city.
It said the negotiations between local dignitaries from Tabqa and the SDF have not reached any results yet.
The SDF led by the Kurdish fighters and the US coalition has been fighting against the IS in Syria for months, with the aim of stripping the group of its main stronghold in Raqqa.
The US carried out several airdrops of forces on Kurdish-held areas to back the Kurdish groups in their battles against the IS in Raqqa.
Two days ago, pictures of US soldiers and vehicles were seen in the predominantly-Kurdish city of Qamishli in northeastern Syria.
The Syrian government repeatedly said it deems the US as a force of occupation, as it entered Syria without coordination with the administration of President Bashar al-Assad.