A handout picture made available by the Syrian government’s official Syrian Arab News Agency (SANA) on April 14, 2014, shows Syrian citizens and policemen inspecting the scene of a car bomb in Homs. (SANA/via European Pressphoto Agency)

— As the Syrian army steps up its assault on the last rebel-held areas of Homs, those holed up inside say they fear that the city, once dubbed the capital of the revolution, is close to slipping completely from their grip.

Jets bombarded pro-opposition neighborhoods of the Old City on Wednesday, as cornered rebels responded with mortar fire, convulsing Homs in the worst violence the city has seen in months, residents said.

Opposition figures and activists said those remaining — fewer than 1,000 people, the vast majority of whom are fighters — are for the most part looking for an exit strategy. But without one at hand, they have no choice other than to dig in. A hard-core few have vowed to fight to the end.

The rebels have been steadily penned in and besieged over the past two years. But if the government captures their last foothold in the Old City, once a bastion of the rebellion against President Bashar al-Assad, it would be a painful and symbolic loss for them.

The government’s long-term strategy to crush the rebellious areas of Homs — by cutting off food and other supplies — is a familiar one. Similar methods have been used to secure restive suburbs of Damascus, Syria’s capital, forcing rebels to accept cease-fires that some say amount to surrender.

Hundreds rallied in the Syrian capital ahead of the country's Independence Day to show solidarity with President Bashar al-Assad. (Reuters)

However, in Homs, negotiations on a reconciliation deal, underway for weeks, have stalled. The opposition complains that the government has never taken the negotiations seriously and is under pressure from pro-regime militias to secure the area by force.

Spirits beaten down

A series of murky events in recent weeks helped clear the way for a military offensive by pro-Assad forces — sparking speculation within the opposition that a government hand was behind them. Others point a finger at rebels who disagreed with efforts to reach a cease-fire.

First, an apparently accidental explosion wiped out a number of rebel leaders. Then a Dutch priest who had refused to leave the opposition areas was assassinated. Those incidents were followed by a car bombing in a pro-government area, which occurred immediately before the bombardment by Assad’s forces began.

With their spirits beaten down, hundreds of rebels have accepted government offers to hand over their weapons, activists and Syrian state media said, weakening the resolve of some of those who remain in the city. There has been a slow and steady exodus since mass evacuations were conducted in February under the auspices of the United Nations.

At least 300 fighters have left in the past month, according to three activists in the city, and one put the number at nearer 1,000. Virtually no civilians remain, they said. Fighters turn themselves in at a school, where they wait to be cleared, and hundreds remain in detention, the activists said.

The opposition All4Syria news site said 500 had surrendered their arms since last month, and it predicted that rebel-held areas of the city would fall within the week. The Syrian Arab News Agency said 100 had surrendered in the past 10 days.

“As a result of the scarcity of cigarettes and food, and the long duration of the siege, the regime has seduced them,” said Abu Bilal, an opposition activist in the Old City.

Many said the accidental explosion, which killed more than two dozen rebels this month, was a turning point. Initially reported as the premature detonation of a car bomb being prepared by rebels, the incident seriously damaged morale in the city’s last major pocket of resistance. Abdulqadr al-

Jumaa, a prominent rebel leader, and other senior fighters died in the blast.

Those killed in the explosion were close to the Rev. Frans van der Lugt, a Dutch Jesuit who refused to leave the Old City, rebels said. A day later, he was assassinated. His presence in the Old City had provided some comfort to the opposition, and after he was killed, rebels predicted that it would not be long before a government offensive began.

Negotiations stall

Negotiations on a reconciliation plan for Homs have been underway for a month, but a deal fell through last week, rebels say.

An opposition negotiating team, headed by a local doctor, had outlined an agreement with terms similar to truces elsewhere, including the withdrawal of heavy weapons and the establishment of joint committees to govern the area. Pro-government militias were particularly opposed to such a deal.

Then, a double car bombing struck a pro-government neighborhood, killing 25 people, according to Syrian state television. That marked the end of negotiations and the beginning of an apparent military assault. As airstrikes and artillery fire increased, rebels were described as looking for a way out.

“They are trying to look for a truce. They want an end to the blood,” said Razan Shalab al-Sham, a director of the Syrian Emergency Task Force, a pro-rebel lobbying group, who was in touch with fighters overnight. “They don’t have enough weapons to hold on.”

Sham said her organization has contacted the U.S. State Department to request that it apply pressure for a cease-fire that would allow rebel fighters to leave and the wounded to be evacuated.

“It’s nearly impossible for opposition fighters to last for a long time in the Old City,” said one activist, who spoke on the condition of anonymity for security reasons. “Many fighters left the siege, and the rest are not able to fight back for long. They know that.”

Some remain steadfast

Government forces have made small advances recently in the Old City. Abu Bilal, who uses a pseudonym for security reasons, said the army took two buildings in the neighborhood of Wadi al-Sayeh about noon Tuesday. It was the army’s first push into the Old City since the Khalidiya neighborhood fell to the government last summer.

But some rebels might prove difficult to dislodge.

In a video posted online Tuesday, one fighter sings hauntingly about how the rebels will remain steadfast. “We will keep fighting with everything that God gave us: strength, patience, so that we execute the victory,” he says later. “May God keep us on our feet.”

Abu Bilal said that three rebels were killed Tuesday and 10 were wounded but that there were significant casualties on the regime side, too. Opposition fighters in the surrounding countryside attempted to rally.

“Our beloved Homs is in danger. . . . Our enemy is at their door,” Rawad Ahmad Al Kassah, a rebel commander in the countryside to the north said in a statement. He called for rebels to put aside their differences and to organize joint operations.

“It is not too late brothers. Let us unify our efforts and regain Homs as the capital of the Syrian revolution.”

But even the most determined rebels were getting ready for the end. Inside the city, some of the fighters who didn’t wish to leave were “preparing themselves with suicide belts,” Sham said. “If the regime manages to cross the lines, they will use them as a last resort.”

Tania Majdalani in Beirut contributed to this report.