ISTANBUL/BEIRUT - Syria's fractious opposition elected a new leader on Saturday but rebel groups were reported to be fighting among themselves in a sign of growing divisions on the ground between factions trying to topple President Bashar Assad.
The Syrian National Coalition chose Ahmad Jarba as its president after a close runoff vote that reinforced the influence of Saudi Arabia over a perpetually divided opposition movement that has struggled to convince its Western and Arab allies that its fighters are ready to be given sophisticated foreign weaponry.
Jarba is a tribal figure from the eastern Syrian province of Hasaka who has Saudi connections. He defeated businessman Mustafa Sabbagh, a point man for Qatar, which has seen its influence over the opposition overshadowed by the Saudis.
"A change was needed," Adib Shishakly, a senior official in the coalition, told Reuters after the vote held at an opposition meeting in Istanbul.
"The old leadership of the coalition had failed to offer the Syrian people anything substantial and was preoccupied with internal politics. Ahmad Jarba is willing to work with everybody."
The Muslim Brotherhood, the only organized faction in the Syrian political opposition, has seen its mother organization in Egypt thrown out of power in Cairo this week along with President Mohamed Morsi.
But the Brotherhood representative, Farouq Tayfour, was elected one of two vice-presidents of the Syrian National Coalition in a sign the group still retains influence in Syrian opposition politics.
In northern Syria, rebels clashed with an opposition unit linked to al-Qaida, activists said, in a battle that signals rising tensions between local people and more radical Islamist factions.
Fighting between rebel groups and government forces was reported in Homs and around Damascus in a war whose casualty toll has now topped 100,000.
The rebel infighting comes as forces loyal to Assad have made gains on the battlefield and drawn comfort from the downfall the Muslim Brotherhood in Egypt.
The Islamic State of Iraq and al-Sham (ISIS), a new al-Qaida franchise, has been working to cement power in rebel-held parts of northern Syria in recent months.
ISIS units have begun imposing stricter interpretations of Islamic law and have filmed themselves executing members of rival rebel groups whom they accuse of corruption, and beheading those they say are loyal to Assad.
As hostilities drag on and resources grow scarce, infighting has increased, both among opposition groups and the militias loyal to Assad, leaving civilians trapped in the middle.
The latest internecine clashes were in the town of al-Dana, near the Turkish border, on Friday, local activists said. An opposition group known as the Free Youths of Idlib said dozens of fighters were killed, wounded or imprisoned.
The Syrian Observatory for Human Rights, an opposition monitoring group, said that the bodies of a commander and his brother, from the local Islam Battalion, were found beheaded. Local activists working for the British-based group said the men's heads were found next to a trash bin in a main square.
The exact reasons for the clashes have been hard to pin down, but many rebel groups have been chafing at ISIS's rise in power. It has taken over the once dominant Nusra Front, a more localised group of al-Qaida-linked fighters that had resisted calls by foreign radicals to expand its scope beyond the Syrian revolt to a more regional Islamist mission.