Syrian rebels occupying the Salaheddin area of Syria’s largest city and economic powerhouse were braced Thursday for a devastating attack by government troops, perching behind a fragile checkpoint of trash cans, rubble and a mutilated poster of President Bashar al-Assad.

Fighters armed with Kalashnikov rifles and dressed in a mixture of military and civilian clothes were spread across this once-populous district, speaking with both resilience and realism about their prospects of surviving and taking a city crucial to the government’s survival.

“We believe that everyone who dies for his country is a martyr,” said a rebel commander known as Jarnas, his leg swollen from what he said was a bullet wound sustained in a skirmish with government forces a month earlier. “We are more brave, and this is the reason we are much more powerful.”

Hours after he spoke, Aleppo boomed with bursts of heavy automatic weapons fire laid over the constant sound of an observation helicopter circling high overhead.

As in Damascus last week, a rebel offensive has for the first time brought war to the heart of the city and challenged the myth of total government control — but, just as in the capital, Assad’s forces are fighting back.

“When the French were occupying Syria, I never saw what I have seen in the past three days,” said an elderly rebel supporter named Mohammed, outside a Salaheddin apartment where the tail of a regime shell lay under the hole it had punched in the ceiling. “If they give me a pistol, I am going to fight.”

Salaheddin is one of several districts that exploded last week in what appeared to be a big rebel operation to send fighters into the city to join up with small groups of existing forces there. Jaffer, a Salaheddin builder turned rebel, said he had been part of a group of fewer than 10 local men who, under the direction of an army defector, had initially expelled government forces from the area.

“We were eight, but we are not anymore,” he said, adding that reinforcements had since come in from the countryside around Aleppo, where rebels have established large areas of control. “Now we are much more.”

Analysts say Aleppo is in some ways as important a prize as Damascus because of its size, its commercial importance and the prominent merchants and regime linchpins who live there. It would also be crucial to the rebels as a bridgehead for personnel and supplies routed in from the nearby border with Turkey, whose government is a strong opponent of Assad.

In yet another mirror to Damascus, Aleppo is now a patchwork of localized conflict, with death and mayhem in one district and the appearance of something like normality in the next.

On the alternative road into the city from the airport — the main highway is closed for security reasons — four corpses lay on the edge of the asphalt, young men milling around them and apparently paying them little attention.

In the city center, some shops were shuttered in the district around the Sheraton hotel and the Christian area of the old city, but vendors who still felt sufficiently secure to fill the sidewalks with children’s bikes and mannequins in tight women’s jeans.

In Salaheddin, by contrast, many residents have left and those who remain have become inured to the lack of electricity, the sporadic gunfire and the threat represented by what the rebel fighters say is an army base in a football stadium just outside the district’s boundaries.

“If I hear shooting now, I don’t care,” said an activist known as Tammouz, after a dash across a street to avoid gunfire audible not far away. “People are not worried, because they already lost everything that makes life beautiful.”

Amid the tension and foreboding, many of the rebel fighters appeared strangely calm, the composure perhaps of men who are certain of their fate and have prepared for it. As activists handed the remaining residents photocopied sheets telling them what to do in the event of a shelling attack, the rebel commander Jarnas explained how his troops were rearming themselves with rifles and ammunition bought from defecting government soldiers.

“We are using bullets that cost $3,” he said, reflecting on an asymmetric conflict in which one of the main rebel strategies appears to be attritional exhaustion of the government’s reserves of men, supplies and will. “And they are coming with bombs that cost thousands.”

— Financial Times