US-backed local forces fighting Islamic State in Syria said today they had taken full control of a former Syrian army airport near the city of Tabqa along the Euphrates River. <br/><br/>The Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab militias supported by a US-led international coalition, said in a statement they had seized the air base.<br/><br/>Earlier, a SDF spokesperson said its fighters had seized "60 to 70 per cent" of the airport but were still engaged in intense clashes with the ultra-hardline militants inside the air base and on its outskirts. <br/>