BEIRUT (AP) -- Heavy fighting broke out Monday between rival jihadi groups in an oil-rich eastern Syrian province bordering Iraq, forcing many residents to flee, activists said.
The Britain-based Syrian Observatory for Human Rights said the fighting concentrated on the eastern parts of Deir el-Zour province. An activist based in the province who goes by the name of Abdul-Aziz Sheik said many tribesmen have joined the battle on the side of the Syrian al-Qaida affiliate known as the Nusra Front, which is fighting an al-Qaida breakaway group, the Islamic State of Iraq and the Levant.
The infighting comes ahead of a presidential election on June 3 that current President Bashar Assad is expected to win. The vote gives him a mandate to continue his violent crackdown on rebels in the Syrian civil war, which activists say has killed more than 150,000 people.
A German Foreign Office official said Berlin would not allow Syrians in Germany to vote in the election remotely.
"From the point of view of the government, this election is not democratically legitimized," said the official who spoke on condition of anonymity in line with the department's policy.
In Deir el-Zour province, no side has made major gains since last week's capture of much of the western parts of the province by the Islamic State, according to The Observatory and Sheik.
Sheik said that last week, powerful tribal leaders called on both sides to agree on a truce that would begin Saturday. The Nusra Front agreed while the Islamic State gave no answer, making many tribes turn against them, Sheik said via Skype.
"People are fleeing in boats from the eastern side to the west of the river," he said referring to the Euphrates River.
The Islamic State has been clashing with the Nusra Front, their former allies, for nearly two weeks in Deir el-Zour. The fighting has killed more than 230 people and displaced 100,000 according to The Observatory.
On Sunday, the Islamic State's official spokesman strongly criticized its parent organization's head, Ayman al-Zawahri, for siding with the Nusra Front.
In an audio message posted on militant websites, Abu Mohammed al-Adnani, accused al-Zawahri of being responsible "for shedding Muslim blood" and urged him to step down for the election of another leader. The tone and level of criticism against al-Zawahri by a fellow jihadi were rare.
The crisis between the two jihadi groups escalated after al-Zawahri recognized the Nusra Front as al-Qaida's official branch in Syria and urged the Islamic State's leader, Abu Bakr al-Baghdadi, to withdraw his men from there. He also ordered the establishment of an independent Islamic court to settle the issue, a move rejected by al-Baghdadi.
Al-Adnani considered the decision by al-Zawahri a "fatal mistake" that led to infighting between the two groups that left more than 4,000 people dead over the past months.
"We call on you to undo your fatal mistake ... because you are the one who kindled sedition, you are the one who will extinguish it," al-Adnani told al-Zawahri.
Associated Press writer Kirsten Grieshaber contributed to this report from Berlin.
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