Beirut, AP—Weakened Syrian rebels are making their last desperate stand in Homs, as forces loyal to President Bashar Al-Assad launch their harshest assault yet to expel them from the central city, once known as the capital of the revolution.

Some among the hundreds of rebels remaining in the city talk of surrender, according to opposition activists there. Others have lashed back against the siege with suicide car bombings in districts under government control. Some fighters are turning on comrades they suspect want to desert, pushing them into battle.

“We expect Homs to fall,” said an activist who uses the name Thaer Khalidiya in an online interview with The Associated Press. “In the next few days, it could be under the regime’s control.”

The fight for Homs underscores Assad’s determination to rout rebels ahead of presidential elections now set for June 3, aiming to scatter fighters back further north toward their supply lines on the Turkish borders. Assad’s forces are building on gains elsewhere—they have been able to almost clear rebels from a broad swath of territory south of Homs between the capital, Damascus, and the Lebanese border, breaking important rebel supply lines there. Rebels have also capitulated in several towns around Damascus after blockades that caused widespread hunger and suffering.

Homs, Syria’s third largest city, is a crucial target. Located in the country’s center, about 80 miles (130 kilometers) north of Damascus, it links the capital with Aleppo in the north—the country’s largest city and another key battleground. But rebels still control large areas of the countryside in the north and south and have consolidated around the Turkish and Jordanian borders.

“A total loss of Homs would represent a serious loss to the opposition,” said Charles Lister, visiting fellow at the Brookings Doha Center.

“The military has maintained a steadily significant focus on Homs precisely due to this importance,” said Lister. “This has been all been part of a very conscious strategy of encircling, besieging and capturing areas of strategic importance,” particularly urban areas.

For well over a year, government forces have been besieging rebels in the string of districts they hold in the city center, around its ancient bazaars.

Just over a week ago, troops loyal to Assad escalated their assaults on rebel districts, bombarding them with tank and mortar fire and bombs dropped from military aircraft. Syrian forces have so far advanced into two areas, Wadi al-Sayih and Bab Houd.

Online video footage showed explosions as projectiles smashed into buildings, sending up columns of white smoke. Angry rebels are heard shouting that they have been abandoned and singing that only God could help them. The footage corresponded to other AP reporting on the events.

Activists said it was the fiercest assault since last summer, when Syrian forces retook the rebel-held Homs neighborhood of Khalidiya.

The death toll from fighting isn’t known, because neither side reports losses.

If Assad’s forces take Homs, it would be a major boost as he prepares for the upcoming election, fueling the image his government has sought to promote that he is capable of eventually winning the relentless conflict. The war is now in its fourth year, with more than 150,000 people killed and a third of Syria’s population driven from their homes. Assad is expected to easily win another seven-year term in the June 3 election, which the opposition and the United States have already declared a farce aimed at giving Assad a veneer of popular support.

Inside Homs, rebels have been deeply weakened by months of blockade around their strongholds and the loss of their supply lines from Lebanon in March, after Syrian forces seized the border town of Zara.

Hundreds of fighters surrendered during a series of UN mediated truces that began in November. An estimated 800 to 1,000 fighters left alongside hundreds of civilians who were evacuated from rebel-held parts of the city, according to activists and an official in the Homs province. The rebels remaining in the city are predominantly from the Nusra Front, an Al-Qaeda affiliate, and other Islamist factions.

One rebel fighter in the city, who uses the nickname Abu Bilal, estimated there are 1,000 rebels who remain in Homs, but the number could not be confirmed. Like Khalidiya and other activists and rebels, he spoke on condition he be identified only by his nickname for fear of retribution.

An activist in Homs, Abu Rami, said rebels wanting to leave had weakened the spirits of others struggling to bear the blockade.

“They tempted them with food and drink, and saying, ‘Don’t you want to see your families?'” he said over Skype from the city. “[It] really did weaken hundreds of them, and it affected the morale of the rest of the rebels.”

Dozens more fighters are now trying to surrender, according to Abu Rami and Khalidiya. The fighters reached out to contact the governor of Homs, Talal Barazi, and Reconciliation Minister Ali Haidar, who handles such cases.

“We asked the regime if we could surrender and leave for the countryside,” said Khalidiya.

“So far we don’t have a clear answer,” said Abu Rami, who is opposed to leaving but is helping mediate for the others.

Barazi’s office said there was “absolutely no contact” with gunmen. It wasn’t immediately possible to contact Haidar.

Some rebels have escalated suicide car bombings in government-controlled areas dominated by Alawites, the minority Shiite offshoot sect that Assad belongs to. At least five such bombings in April killed more than 60 people, one of the bloodiest months for residents in government-controlled areas, a local reporter there estimated. The most recent, on Friday, killed 14.

“We are killing them, those rotting carcasses,” said Abu Bilal, the fighter.

The bombings have another aim, sparking fighting that prevents any truce that would allow rebels to desert, Abu Bilal said.

“Some of us are against those deserting. We are fighting so they can die in it,” said Abu Bilal.

Homs’ saga traces the arc of Syria’s uprising. It quickly embraced the uprising against Assad’s rule after it began in southern Daraa province in March 2011. Tens of thousands joined anti-Assad protests in Homs, winning it the nickname of “the revolution’s capital.”

“We carried the spark of the revolution and made it a flame,” Abu Rami said.

After pro-Assad forces violently cracked down on demonstrations, some protesters took up arms, transforming the uprising into an armed rebellion.

Homs has also seen the ever-increasing religious dimension of the conflict, with tit-for-tat sectarian killings in the city where majority Sunni Muslims live alongside Christians and Alawites.

Most recently, on April 7, a masked gunman killed a beloved, elderly Dutch priest, Jesuit Father Francis Van Der Lugt, who lived in a monastery in a rebel-held district, staying alongside civilians who were unable to leave.

Khalidiya, the activists, said Homs is lost, now they have to save the fighters.

“We are more scared that the regime [forces] will kill everybody than we are worried about the fall of Homs.”

But Abu Rami said he’d rather die.

“If they come, then we are all going to be martyrs. We can lose an area, and we can regain it. But the most important thing is not to kneel.”