Syrian Kurds made rapid advances in the north on Tuesday, expelling jihadists from a string of villages, as mistrust between Kurds and Arabs grows, a watchdog and activists said.
Fighting hit a series of ethnically mixed villages in the northern province of Raqa on the border with Turkey, the Syrian Observatory for Human Rights said.
Kurdish fighters expelled jihadists from several villages around the majority Kurdish town of Cobany, the watchdog said.
In the village of Jalbeh they captured jihadist emir Abu Raad and several of his men, it added.
In Hasakeh province further east, Kurdish-jihadist fighting raged for a seventh day in the Jal Agha area and other parts of the majority Kurdish province.
The latest clashes come a week after fighters loyal to the Committees for the Protection of the Kurdish People (YPG) expelled the jihadist Al-Nusra Front and the Islamic State of Iraq and the Levant from the strategic Kurdish town of Ras al-Ain in Hasakeh province.
Fighting has since spread to several areas of Raqa province to the west.
At least 70 people have been killed in the fighting, most of them jihadists, the Observatory said.
"What we are seeing is the spreading of fighting between Kurds and jihadists westwards, across areas that are home to both Arab and Kurdish communities," Observatory director Rami Abdel Rahman told AFP.
Although the fighting is between jihadists and organised Kurdish forces, there is "a growing gulf between Kurdish and Arab residents of these areas," Abdel Rahman said.
"The battle is morphing from a fight between the YPG and the jihadists to a struggle between Kurds and Arabs as a whole."
Prior to the outbreak of the 2011 revolt against President Bashar al-Assad's rule, the Kurds had suffered discrimination for decades.
When the revolt erupted, one of the first measures taken by Assad was to grant Syrian citizenship to the many Kurds who had previously been denied it.
Then, starting in mid-2012, Assad's forces withdrew from Kurdish regions which are now run by local Kurdish councils.
The Kurds, who represent about 15 percent of the Syrian population, have since walked a fine line, trying to avoid antagonising either the regime or the rebels.
But as abuses by jihadist groups have mounted in areas that have fallen out of Assad's control, the Kurds announced they would seek a temporary autonomous state and establish a constitution.
The move highlighted the depth of mistrust that has built up between many Kurds and the Syrian opposition over what they see as a lack of representation for the minority community, activists say.
"There hasn't been real trust at the political level since the start" of the revolt, Kurdish activist Havidar told AFP via the Internet.
"We (Kurds) all stood by the revolution but unfortunately the Syrian opposition... has played games with the Kurds... and marginalised them," Havidar said.
As a consequence, "there is a very obvious divide now" between Kurds and Arabs, he said.
A leading Kurdish member of the opposition National Coalition said he wanted to see an end to the in-fighting in areas outside of government control.
"Of course, the one benefiting the most from all these operations is the regime," Abdel Basset Sayda told AFP.
"We need to preserve Syria's unity."
Neither the YPG -- which grew out of the main Kurdish party, the Democratic Union Party (PYD) -- nor the jihadists command the support of all Kurds or Arabs in northern Syria, Sayda said.
But their visions for Syria appear irreconcilable. While the PYD has announced plans for a temporary autonomous state in Kurdish areas, the jihadists seek the creation of an Islamic state across Syria.
"Both sides have their own plan... But we need calm... We call on all sides to go to dialogue," Sayda said.