BEIRUT -- Kurdish and rebel militiamen were battling Saturday for control of a northeastern Syrian town in a dramatic illustration of the deep fissures within Syria's armed opposition.
A Kurdish umbrella group, the Kurdish National Council, called Saturday on the rebel leadership to exert influence with its fighters to cease their attack on Ras al-Ayn, along Syria's remote northeast border with Turkey.
The Kurdish group demanded that the opposition leadership "put pressure on these armed groups to stop this criminal war, which is detrimental to the principals and objectives of the Syrian revolution."
Whether the request will make any difference remains to be seen. Rebel combatants in Syria are extremely decentralized and generally follow no central command.
Several days of rebel-Kurdish clashes in Ras al-Ayn have left at least 33 combatants dead, according to the Syrian Observatory for Human Rights, a British-based pro-opposition monitoring group.
The Kurdish and Arab militiamen share a deep mutual mistrust, though both profess to back the downfall of Syrian President Bashar Assad.
The Kurds, a non-Arab ethnic minority, say the Arab rebels are using tanks and artillery to attack Kurdish positions and civilian neighborhoods in Ras al-Ayn, about 320 miles northeast of Damascus, the capital. The Kurds also accuse the rebels of collaborating with Turkey, which has long fought a Kurdish rebellion of its own, in a bid to crush emerging Kurdish leadership in northern Syria.
Ras al-Ayn, home to about 50,000 people before intense fighting broke out last year, is just across the border from the Turkish town of Ceylanpinar.
Arab rebels also harbor doubts about the Kurdish fighters. Some suspect that the Kurdish militiamen remain loyal to Assad. The president's forces retreated in July from a vast swath of the Kurdish north, effectively ceding rule to Kurdish parties without a shot being fired. But the Kurdish groups in Ras al-Ayn deny being Assad backers and say they support the revolution.
Many secular Kurds also object to the ultraconservative Islamist bent of some of the Arab rebel battalions. Several extremist militant groups, reportedly including al-Qaida-linked Al Nusra Front, are said to be among the rebel factions operating in Ras al-Ayn. The Obama administration has labeled Al Nusra Front a terrorist group.
Turkish authorities have allowed Syrian rebels to use Turkish territory to move personnel and weapons into Syria. But Turkish officials have expressed alarm about the rise of Kurdish factions in Syria.
The Turkish government has been engaged in a decades-long war against the autonomous-minded Kurdistan Workers Party, or PKK. Many Syrian Kurds support the PKK and its jailed leader, Abdullah Ocalan, who is serving a life term for treason in a Turkish prison. Some Syrian Kurds have even enlisted in the PKK.
Aside from Ras al-Ayn, Kurdish and Arab forces have clashed elsewhere in the north, notably in the city of Aleppo.
Many Syrian Kurds view the prospect of Assad's downfall as a chance to gain long-desired political autonomy. But some Arab rebels are hostile to Kurdish ambitions for autonomous rule, saying such a step could weaken a post-Assad Syria.
Special correspondent Lava Selo contributed to this report.