DAMASCUS // Military operations to crush an anti-government uprising have spread to Syria's tribal heartlands as tanks and infantry surround the remote town of Abu Kamal on the border with Iraq.
Armoured vehicles and soldiers have been in the main square of Deir Ezzor city 420km north-east of Damascus for some weeks, forming a defensive ring around a large statue of the former president Hafez al Assad. Now, according to residents and activists, forces backed by tanks have arrived at Abu Kama on the eastern edge of Deir Ezzor province, according to residents and activists.
The move pitches Syria's armed forces squarely into the country's Sunni Arab tribal zone and its crucial oil-producing region, which has grown increasingly volatile.
"Deir Ezzor is hot with protests. The province is boiling away with anti-regime sentiment," said an analyst from one of the major eastern Syrian tribes. "It's a delicate situation and it could turn very bad very quickly."
Although Syria's Arab clans are not as strong as they once were, many customs have been retained, including a strong desire for revenge if tribe members are killed unjustly.
There is also long-simmering discontent as poverty has risen, accelerated by years of drought that have left proud farming families dependent on United Nations food and aid handouts while even small government cash grants are skimmed by corrupt officials, tribal families say.
At least eight protesters in the province have been shot dead by security forces and about 50 wounded since the start of May, according to human-rights monitors. At least one security officer has also been killed, the government says, with more apparently injured when they were attacked by a crowd armed with stones and knives this month.
Syrian military units have already assaulted dissident cities, including Deraa, in the south, and Jisr al Shughour, on the northern border with Turkey, as part of a government strategy to solve an unprecedented crisis through force and vague promises of reform.
But Deir Ezzor and the Arab tribes pose a particularly difficult problem, according to one civil rights activist with extensive contacts in the area.
"It's hard for the army to carry out operations there because it's very remote, and the tribes have the border with Iraq which they are used to crossing illegally and they can bring in weapons that way too if they want," he said. "The government realises it has to tread carefully."
Many leading clan figures in Syria hold joint Syrian-Saudi citizenship, adding another layer of sensitivity. Saudi Arabia has so far been silent on the Syrian uprising but may speak out if its citizens are caught up in violence.
Cross-border tribal connections meant that, for much of the US-led war in Iraq, smuggling of weapons and fighters from Syria was a major complaint of the American military and Iraqi government. The Syrian authorities now face the prospect of that happening in reverse. Syrian customs officials say they have already seized shipments of machine guns, sniper rifles, night vision scopes and grenade launchers at the Iraq border.
The Syrian activist said fewer protesters had been killed in Deir Ezzor than many other places because security units understood they risked sparking a broader uprising with lethal violence.
"Elsewhere in the country protesters are shot in the head and chest, which makes it seem there is a shoot-to-kill policy," he said. "In Deir there are more leg wounds - when the security shoot they try to injure, so they don't have the tribes coming for them."
Nonetheless, heavy-handed action by security forces appears to have played a part in bringing tens of thousands of protesters on to the streets in Deir Ezzor city, Abu Kamal and Mayadin, the three urban centres along the Euphrates River valley. Throughout March and April, Deir Ezzor did not move, then, in the first week of May a small protest took place.
Activists say the security forces immediately closed the Osman bin Afan mosque in Deir Ezzor city, which served only to bring more protesters out on the streets, angry that a community meeting place and house of worship had been shut. Government forces then moved to break up a three-day sit-in outside the mosque, killing two demonstrators and wounding 10 more.
As anger grew, security units placed video cameras inside the mosque on May 12, further stoking a sense of outrage among many residents. On May 20 tensions overflowed in Abu Kamal, with demonstrators setting fire to the Baath party headquarters and releasing prisoners from the town jail. Three protesters were shot and killed.
"The security basically had to run away and for a while Abu Kamal was under protester control," said the tribal analyst. "The government cannot afford to let that happen again."
The following week thousands took to the streets across the province, and posters of the Hizbollah leader Hassan Nasrallah were burnt publicly in Abu Kamal. A close ally of the Syrian regime, Mr Nasrallah had sided with the government against protesters in a speech.
It had a sectarian undertone, with Sunnis unhappy that the head of a Lebanese Shiite militant movement would interfere in Syria's affairs.
The tribes insist they are religiously moderate, their ancestors having fled from Saudi Arabia when the kingdom was formed, to escape its hardline brand of Wahhabism.
A majority of the population in Deir Ezzor has not joined anti-government protests, and, while some influential tribal figures have openly backed demonstrations, others continue to support the government.
However, that support has sometimes times been pointedly lukewarm. In a statement earlier this month, 50 leading Syrian sheikhs paid tribute to those killed in the uprising, civilian and military.
While rejecting foreign intervention, it did not simply repeat the official line of blaming armed Islamic groups and ignoring civilian suffering.
"The tribes may not be anti-government but they were also saying they are not going to be pro-government for the sake of it," the tribal analyst said. "They can go either way."