Syrian rebels
Syrian rebelsReuters

A U.S.-backed Syrian alliance of Kurdish and Arab militias on Sunday took control of a military airport in northern Syria held by Islamic State (ISIS), Reuters reported.

The Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab militias supported by a U.S.-led international coalition, said in a statement they had seized the air base.

Earlier, SDF spokesperson Talal Silo said its fighters had seized "60 to 70 percent" of the airport but were still engaged in intense clashes with ISIS jihadists inside the air base and on its outskirts.

The SDF have been battling ISIS near the Tabqa dam and air base west of the city of Raqa, which is the jihadist group’s de facto capital in Syria.

The Pentagon said last Wednesday it had for the first time airdropped local ground forces behind enemy lines near Tabqa in northern Syria, in a move aimed at retaking the major dam.

ISIS captured the Tabqa Dam, also known as the Euphrates Dam, which is about 40 km (25 miles) upstream from Raqa and the air base, at the height of its expansion in Syria and Iraq in 2014, according to Reuters.

The United Nations warned this year of catastrophic flooding in Syria from the Tabqa dam, which is at risk from high water levels, deliberate sabotage by ISIS and further damage from air strikes by the U.S.-led coalition.

An SDF spokesman denied on Sunday that coalition strikes hit the structure of the dam, adding the air drop landing last week was conducted to prevent any damage to the main structure by engaging the militants away from the dam.

In late 2016, an air strike by the international coalition near Tabqa dam killed key ISIS commander Abu Jandal al-Kuwaiti.