The people who live on Aleppo’s fiercest frontline have fled. Only the fighters remain

In Aleppo, Assad's forces are locked in bloody battle with a splintered opposition. Kim Sengupta, the only foreign reporter in the heart of Syria's second city, reports

There was a strange quietness to Salaheddine in between the bursts of ferocious fighting. The strips of cloth that curtain off the narrow, twisting alleys from the sight of the regime's tanks and guns rustled in the wind, there was a faint noise of traffic in the distance. The only human voices, however, were hurried conversations in doorways between fighters; the people who lived here have gone.

The calm was shattered by a few shots, snipers at work. This was followed immediately by deafening rifle fire and then the deep boom of shells and mortars crashing into buildings in neighbouring streets. There were roars of "Allah hu Akbar" from the rebels as ambulances went careering by, playing religious and protest songs in full volume.

Defiance is the theme in the most violent battleground in Syria's civil war at present, the Salaheddine district of Aleppo, the bloody focal point in the struggle for the country's largest city and commercial capital, a symbolic and strategic prize craved by both sides.

"F*** you, sniper!" shouted an opposition activist in the car that we were travelling in, crouching low in our seats to avoid shots supposedly coming our way. What we got, instead, was a rocket-propelled grenade, sailing far overhead to hit the ground floor of a house, adding to the pock-marked and burnt architecture of the area.

The Independent was the first international news organisation to enter Salaheddine since Bashar al-Assad's regime began its offensive to clear the main opposition stronghold in the city. Standing on the road where most of the fighting was taking place, Sheikh Taufik Shiabuddin, the district's rebel commander, said he welcomed a chance to refute "Assad's lies". He counted off the triumphs so far on the fingers of his hand. "We have destroyed two tanks, seven armoured carriers and killed 200 of their soldiers. They had attacked us with a force of 3,000 and they cannot get in. We shall be going forward to them soon, the enemy is suffering," he said to chants of "Takhbir" (call to God) from his followers, who gathered around him.

The regime's forces may be suffering, but they still appeared to have a lot left in reserve, judging by the regularity with which mortar and light-artillery rounds came whizzing over. A helicopter gunship made several passes overhead, but it would have been difficult for the pilot to pick out targets in such confined quarters and it flew off to attack elsewhere.

Looking from the fourth-floor balcony of an abandoned flat, curtained like almost every other balcony in the area, one could see a row of eight green Syrian army tanks, possibly Russian made T-55s, with their barrels pointed towards the streets of Salaheddine. "They have been firing from the tanks, but all they are hitting are empty buildings" said the Sheikh's brother, Ahmed. "We have lost some people for sure, 15 martyrs and 40 wounded. They have tried to bring their tanks in here and we've hit them hard. Assad's people know we are waiting."

All the stores in street were shuttered apart from one with a "special offer" on display – trays of Molotov cocktails. Standing among the bottles, 19-year-old Amir Mohammed Hasif explained how they were made and added: "My three sisters helped make them. They cannot join in the fight, but they want to contribute as much as possible in other ways."

The revolutionaries in Salaheddine came from a number of different battalions, with the Abu-Bakr detachment from the town of Al-Bab among the first volunteers for this extremely dangerous front line. "We are taking only the best ones who offer to come," Abdul Fawzi Hussein said. "We are winning, but Assad is like a wounded snake, he will keep striking. We don't want brave boys to come and then go back to their mothers as martyrs."

It is difficult to ascertain the gains of each side in Aleppo, although some are obviously false – such as Syrian state TV's assertion of "complete control of Salaheddine". The opposition claims to control around 45 per cent of the area and said it will be taking over the remainder in the coming days. The Independent travelled through parts of eastern and south-eastern parts with the rebels seemingly firmly in control.

The revolutionaries were not totally united. One base flew the black flag with gold Koranic inscriptions favoured by extreme Islamists and the fighters there polite but suspicious of strangers. "We know about them, but they keep to themselves," Abdul Fawzi Hussein said. "We shall have to deal with them in the future, but for now our focus is on Salaheddine and Aleppo. If we hold Salaheddine, I am sure, Inshallah, if we lose Salaheddine then we shall have difficulty holding on to other areas we have in Aleppo. We must liberate Aleppo."

Mohammed Numer, who lived in an adjoining area, one of the very few families to stay on there, wondered what will be left. "Salaheddine is the worst, but other places are getting affected as well. We have so little food because the shops are shut, there is no electricity and no water and no medicine. The fighters can live... among all that, but what about the rest of us? Who will look after us? We just wish all this will end," he said.