Updated

A border region with a history of hostility toward the Syrian regime is posing the biggest challenge yet for President Bashar Assad's struggle to crush the revolt against his family's 40-year-rule.

Analysts say Assad will do anything to restore control in the restive northern area bordering Turkey, where mutinous forces are giving a largely peaceful revolt new strength -- and firepower.

On Saturday, thousands of elite troops and tanks believed to be led by his brother sealed off the entrances to the mostly deserted town of Jisr al-Shughour, with soldiers loyal to the regime coming under sniper fire as they approached.

Mutinous Syrian soldiers and police officers remained behind to fight against an expected all-out government assault, a resident said, and unarmed demonstrators were ready to fight "with their hands" in the town just 12 miles from the Turkish border.

While the Syrian uprising is still far from an all out Libya-style insurgency, the mutiny in Jisr al-Shughour raises concerns the 12-week revolt is taking on a new dimension. Jisr al-Shughour's history of Sunni militancy and its proximity to Turkey make it a crucial proving ground for the regime.

Syrian troops backed by tanks, helicopters and heavy armor have been in the area for several days; it was not clear why the army was delaying an assault. In the meantime, a captain and 15 soldiers defected and joined the protesters on Saturday, according to the Local Coordination Committees, which documents Syrian anti-government protests. The report could not be independently confirmed.

Ausama Monajed, a London-based Syrian activist, said the Assads could be worried not just about army defections, but any hesitation to obey shoot-on-sight orders. Human rights groups say more than 1,400 people nationwide have died in the government crackdown since the uprising erupted in southern Syria in mid-March.

"The Assads are reshuffling the army and creating a number of mainly Alawite units made up specifically of people who have been tested and have shown themselves to be hardcore loyalists," he said.

"It is these units that have been sent to Jisr al-Shughour."

Jisr al-Shughour is a predominantly Sunni town with some Alawite and Christian villages nearby in Idlib province. Most Syrians are Sunni Muslim, but Assad and the ruling elite belong to the minority Alawite sect, an offshoot of Shiite Islam.

Jamil Saeb, an activist from the town who was reached by phone, suggested the army was afraid to take on the people who stayed behind because Jisr al-Shughour residents were "known to be exceptionally fierce." He said several army deserters and officers were still there and have vowed to protect unarmed residents.

Idlib's Muslim Brotherhood population rose up against Assad's father, the late president Hafez Assad, in the late 1970s. Jisr al-Shughour itself came under heavy government bombardment in 1980, with a reported 70 people killed. Residents say the numbers were much higher.

The events proved a prelude to a 1982 three-week bombing campaign against the city of Hama that crushed a Sunni uprising there, killing 10,000 to 25,000 people, according to Amnesty International estimates.

"They (regime) have a grudge against Jisr al-Shughour since the 80s," said Saeb.

The government's admission that 120 officers and security officers were killed by "armed groups" in the area gave new cause for concern.

"Syria cannot afford to lose territory where an insurgency or rebel army might emerge," said Joshua Landis, director of the University of Oklahoma's Center for Middle East Studies.

"Damascus will do everything it can to preclude the formation of a Benghazi, which would allow foreign intelligence agencies and governments to begin arming and training a rebel army, as happened in Libya," he wrote in his influential blog, Syria Comment.

Benghazi is the de facto rebel capital in Libya and the center of their strength; Syria's Idlib province is nowhere near that level.

Arab governments, which were unusually supportive of NATO intervention in Libya, have met the Syrian crackdown with silence, largely because Syria is seen as a regional powerhouse with influence on events in neighboring Israel, Lebanon, Iraq. Syria also has an explosive sectarian mix and there are fears that the alternative to Assad would be chaos and sectarian fighting.

"Syria ... is engaging in horrific, revolting attacks on its own people. The region, however, is trying to, behind the scenes, get the government to stop," said U.S. Secretary of State Hillary Clinton.

The White House said the offensive in the north has created a humanitarian crisis and it called on the government to stop the violence and allow the International Committee of the Red Cross free access to the area to care for the wounded, displaced and detainees.

Syria's brutal crackdown has angered the leaders of neighboring Turkey, who accused the Assad regime of "savagery" and have given refuge to more than 4,300 Syrians.

Journalists invited to accompany troops to the north, including an AP reporter, came under fire about a mile outside Jisr al-Shughour Saturday, and the government blamed snipers stationed in nearby hills. No casualties were reported.

Authorities said they have made some arrests and killed and wounded many of the armed men around Jisr al-Shughour, a city of about 40,000 that has been largely abandoned by residents in recent days.

Confirming information out of Syria is difficult. Communications are cut in areas where the uprising is strongest, including Jisr al-Shughour and foreign journalists have been expelled.

Syrian Foreign Minister Walid Moallem called on the United Nations to help his country fight "terrorist groups." In an interview he gave to the Syrianow website, Moallem said he had sent an urgent message to the U.N. chief warning that any Security Council resolution targeting Syria would be considered "intervention in his country's internal affairs."

Negotiations continued Saturday on the draft text of a Security Council resolution proposed by Britain and France calling on all sides in Syria to cease the violence. Russia and China have so far opposed a resolution on Syria and have veto power.

Turkey's military, meanwhile, was making preparations to step in if necessary, to "control and manage" the flow of refugees from Syria. Some wounded Syrians from Jisr al-Shughour or elsewhere were being treated at the state hospital in the Turkish city of Hatay.

One of them, who only identified himself with his first name, Ahmad, told an Associated Press reporter at his hospital bed on Saturday that he was hit by three bullets during a protest in Jisr al-Shughour on June 4.

One bullet had struck him in the neck, and he spoke with difficulty.

"The snipers suddenly started firing onto us from three buildings," Ferah, a Turkish relative, quoted him as saying in Arabic. "I was hit in the neck and chest first, but a third bullet found my right arm when I raised it while on the ground."

"Allah gave me another life," Ahmad said.