Syrian Kurdish and rebel forces, backed by US-led air strikes, advanced on Thursday into Raqa province, where the jihadist Islamic State (ISIS) group has its de facto capital, a monitor said.
"The YPG (Kurdish People's Protection Units) and rebel forces captured 19 villages in Raqa province," said the Syrian Observatory for Human Rights, reports AFP.
"The US-led international coalition played a key role in the advance, bombing the IS(IS) positions and forcing its fighters to withdraw," said Observatory director Rami Abdel Rahman.
The advance comes as Kurdish and rebel forces push outwards from the border town of Kobane, from which they expelled ISIS forces after more than four months of fighting.
Since driving ISIS out of Kobane on January 26, Kurdish and allied forces have taken much of the surrounding countryside in northern Aleppo province and begun pushing east into neighboring Raqa province.
They have captured some 242 villages around Kobane, including the 19 in Raqa province, according to the Observatory.
They are now 25 kilometers (15 miles) from Tal Abyad, another Kurdish-majority border town overrun by ISIS.
Located 65 kilometers east of Kobane, the town is used by ISIS fighters to cross into Turkey.