Kurdish forces are reported to have taken 90 percent of Tabqa city in Syria's Raqqa province from ISIL amid clashes that have left an estimated 19 people dead.

The claim was made by the official spokesperson for Ghadab al-Furat, a Kurdish group fighting under the US-backed Syrian Democratic Forces (SDF), which launched a campaign in October 2016 to retake Raqqa, the de facto capital of ISIL, or the Islamic State of Iraq and the Levant group, in northern Syria.

"After taking the old city, we now control around 90 percent of Tabqa ... we advanced against the ISIL and pushed further to the other parts of the city," Jihan Sheikh, of the Ghadab al-Furat (dubbed Wrath of the Euphrates), told Al Jazeera on Tuesday.

Talal Silo, an SDF spokesman, told Al Jazeera that the Euphrates dam - also known as Tabqa dam - and some neighbourhoods are still controlled by ISIL but ongoing clashes are taking place to fully recapture the city.

"The first, second and third neighbourhoods that make up al-Thawra city, in addition to the Euphrates dam are still under ISIL control, but the battle continues to liberate them," Silo said.

Tabqa city is made up of two parts, the old city and al-Thawra city, which is also known as the new city.

According to Pentagon estimates from last year, the SDF has more than 40,000 fighters.

"Clashes are still taking place, at least 19 ISIL fighters have been killed in the fighting. We managed to recover their weapons, cars and a tank," Sheikh said.

Ahmad, a Tabqa-based activist, told Al Jazeera that at least 131 civilians have been killed in Raqqa in the past 44 days.

"Our city is destroyed. One of the main hospitals in Tabqa was destroyed in an air raid and many field hospitals too.

"What people should know is that south of Tabqa there are oil fields producing millions of pounds a day. Why else would the US back these Kurdish fighters to this extent?"

The Rojava Defence units, another Kurdish group taking part in the campaign, said at least 5,000 civilians fled the fighting and reached safe areas but are in the need of urgent humanitarian aid.

In Rajm Salibi, in the northern Syrian province of Hasakah, at least 24 civilians and SDF fighters have been killed in fighting between the SDF and ISIL, the Syrian Observatory for Human Rights said.

The SDF is trying to retake Raqqa province after capturing the south of Tabqa last week.

ISIL captured Raqqa in January 2014, and took Tabqa's airbase from the Syrian government in August the same year.

It lost the strategic Tabqa airbase , about 45km west of Raqqa, to the SDF last month.

The SDF was founded in Syria's mainly Kurdish northeastern region in October 2015 and is made up of at least 15 armed factions, mostly fighters from the Kurdish People's Protection Units and the Free Syrian Army.

The United Nations recently said in a press release that at least 39,000 newly displaced people fled to the Jib Al-Shaair makeshift camp in Raqqa, where four out of five people are staying in the open air without appropriate shelter.

As the Syrian conflict enters its seventh year, more than 400,000 people have been killed in the fighting and over 12 million Syrians - half the country's prewar population - have been displaced from their homes.