AMMAN Islamist rebels have cut access to a Kurdish area in northern Syria and clashed with Kurdish nationalist PKK fighters whom they accuse of backing President Bashar al-Assad, sources on both sides said on Thursday.
The confrontation threatens to open a new front in Syria's 27-month-old civil war, in which Kurds, who form about 10 percent of the population, have so far played a limited role.
Fighting erupted overnight on the edge of Ifrin, a rugged, olive-growing area on the Turkish border, the sources said. Four people were killed, bringing to at least 30 the death toll from battles and assassinations in the last few days. Dozens more have been taken in tit-for-tat kidnappings, the sources said.
Tensions between Arabs and Kurds, whose relationship is riven by land disputes, especially in eastern Syria, have risen since the uprising against Assad erupted in March 2011.
Thousands of Kurds joined peaceful pro-democracy protests early on in the revolt but the community has mostly stayed out of the armed and largely Islamist insurgency that followed.
Although Kurdish politicians hold senior posts in the mostly Arab Sunni Muslim opposition, attempts to bring the main Kurdish parties into the umbrella Syrian National Coalition have failed, amid rows over how to define Kurdish rights in a future Syria.
Assad, whose minority Alawite sect is an offshoot of Shi'ite Islam, has pulled his troops out of cities in eastern Syria and out of many parts of Ifrin in the northwest, in effect granting the Kurds an autonomy many of them fear losing if he is toppled.
Ifrin was thrust deeper into the conflict when Assad's forces reinforced Zahra and Nubbul, two Shi'ite villages situated between Ifrin and the divided city of Aleppo, as part of an apparent attempt to capture the rural north, a supply line to Aleppo and to various rebel-held areas in the interior.
Lebanese Shi'ite Hezbollah fighters deployed in Zahra and Nubbul. The army also airlifted troops and loyalist militia to an area in Ifrin behind rebel lines, opposition sources said.
Accusing PKK (Kurdistan Workers' Party) fighters of supplying the two villages, Islamist rebels cut main roads from Ifrin to the provinces of Idlib and Aleppo this month, causing prices of basic goods in Ifrin to soar, residents said.
Kurdish farmers are also struggling to market their crops, the sources said, with rebels extorting high fees at roadblocks.
"Ifrin has been sympathetic to the revolution but the rebels are not serving their cause by what they are doing," said Abboud Hakim, a retired government official in Ifrin.
"They accuse the PKK of delivering supplies to Nubbul and Zahra when they themselves let trucks go there if they pay them at the roadblocks," he said.
Rebel sources said the overnight clashes began when PKK gunmen attacked a roadblock held by an offshoot of the al Qaeda-linked Nusra Front near Jindaris, a Kurdish town southwest of Ifrin city, despite a truce brokered two days earlier by Colonel Mustafa al-Sheikh, a moderate Free Syrian Army (FSA) commander.
Under the deal between the FSA and the Kurdish Protection Units, a de facto PKK unit, the siege on Ifrin was to be lifted on Wednesday and both sides were to have freed their prisoners.
An opposition source in northern Syria said the ceasefire deal had little effect because Sheikh had only limited influence on the Islamist brigades which hold sway on the ground.
The PKK, the source said, also seemed to have little interest in the deal, especially after Arab reconciliation delegates sent to Ifrin were reportedly killed a few weeks ago.
Massoud Akko, a Kurdish activist based in Norway, said the conflict in Ifrin had become turf warfare with scant relevance to the Kurdish cause or the aims of the anti-Assad revolt.
"Even if the Kurdish Protection Units have committed violations, it does not justify besieging 150,000 civilians living in over 300 villages," Akko said. "The rebel forces are using the same methods of collective punishment as Assad."
In Aleppo, opposition activists reported the heaviest fighting in months as rebels fought to claw back gains by Assad's forces in several districts. Pro-Assad forces came under attack in al-Sakhour. Fighting also raged in Suleiman Halabi, a district largely held by Assad's loyalists.
(Additional reporting by Erika Solomon in Beirut; Editing by Alistair Lyon)