Beirut: Clashes between Islamist rebel forces and Kurdish militias spread to a second Syrian province on Saturday, activists said, as factional tensions rose in the north of the country.

The fighting is further evidence that the 2011 uprising against President Bashar Al Assad’s rule has splintered into turf wars that have little to do with ousting him and highlight the risk of regionalised conflicts that could have an impact on neighbouring countries.

The new round of fighting broke out in Tel Abyad, a border town near Turkey in the rebel-held Raqqa province. The Syrian Observatory for Human Rights said clashes began after Kurdish militias in the area discovered fighters from an Al Qaida-linked rebel group trying to rig one of their bases with explosives.

The Kurds retaliated by kidnapping several fighters, including the leader of the Islamic State of Iraq and Sham, one of the most powerful Al Qaida-affiliated forces fighting in Syria.

Syria’s ethnic Kurdish minority, meanwhile, has been battling both Al Assad’s forces and the rebels. Kurds argue they are backers of the revolt but rebels accuse them of making deals with the government in order to ensure their security and autonomy during the conflict.

Divided between Iran, Turkey, Iraq and Syria, the Kurdish people are often described as the largest ethnic group without a state of their own.

Kurdish regions have been run by local Kurdish councils since President Bashar Al Assad’s forces withdrew from the areas in mid-2012.

Since then, the Kurds have walked a fine line, trying to avoid antagonising either the regime or the rebels, and focusing on maintaining security while strengthening control over their own affairs.

But this week alone, more than 50 jihadist and Kurdish fighters were killed in fighting in northern Syria, according to a toll released earlier Saturday by the Observatory.

Kurds represent about 15 per cent of the Syrian population.

Security sources have said Al Assad’s next move will be to push on to rebel-held territories near the border areas of northern and southern Syria, for which they are slowly trying to build up forces in the area.

Al Assad’s offensive has been dogged by rebel counter-attacks in the north, even as a string of government victories elsewhere in Syria has shifted the battlefield tide in his favour after more than two years of bloodshed.

Activists said opposition forces advanced on the northern town of Khan Al Assal on Saturday and appeared close to seizing one of the last towns in western part of Aleppo province still held by Al Assad’s forces.

Elsewhere in northern Syria, Al Assad’s forces launched a third day of heavy air strikes on the town of Saraqeb in Idlib province.

Some activists suggested the army may be trying to hammer areas near a critical road leading to Aleppo in order to distract the rebels and bring in supplies to its forces.

Rebels have been blockading government-held areas in Aleppo city, Syria’s largest urban centre. Aleppo has been mired in a bloody stalemate since rebels launched an offensive in the province last year.

Hardline Islamist rebels also appear to be leading the fight to seize Khan Al Assal.

“Perhaps the Islamists are trying to stay out of the spotlight. They’ve been regrouping and naming themselves with numbers, things like ‘the 9th Division’ and so on, but these are the same Islamist radical groups like the Islamic State of Iraq and Sham or the Islamic Front to Liberate Syria,” one opposition activist said, declining to be named.