Aleppo's Old City pharmacist aims to be open for a few hours once a week, despite the explosions, gunfire, rebel or Syrian army roadblocks he needs to negotiate and a chronic lack of supplies.

In a small square surrounded by white stone houses in a Free Syrian Army-held enclave of the city, 27-year-old Zacharias Mohammed Ali has come to check up on his shop, Zacharias Pharmacy, and to "open it for a while."

He and his younger brother have the air conditioning pumping out cool air as they stand behind the counter but in front of half-empty shelves.

There is not a single soul outside, and no customers in the shop. A solitary large, white fish swims in its tank beside the door.

"Most people who live here have fled, there's almost no one in the neighbourhood. But it's good for those who've stayed to have the chemist open. They can come and buy medicine, or even just chat.

"It seems to put their minds at ease a bit. At least, I hope so," says the portly young blue-eyed man.

Ali lives far away in a regime-controlled area. He crosses the front line and a friend on the rebel side picks him up for the drive to the pharmacy.

"On each side they leave me be. I tell them I'm a pharmacist and I go through. Sometimes I have to wait if there's too much gunfire," he adds.

He keeps the shop open for a few hours once a week, which is enough time to check up on everything and to serve some customers.

Enter one local resident, carrying a baby and with small child in tow. The young man, gaunt-cheeked and wearing shorts and sandals, asks for a baby's bottle, a dummy, some plasters and shampoo.

Ali has to tell him there is no more artificial breast milk, but he smiles reassuringly and gives him some advice before he leaves.

"Sometimes the customers call me from home if they need treatment, for a heart condition for example, and I go to see them," he says.

"I haven't received a delivery of supplies since the first day of fighting, at the beginning of Ramadan (late July). At this rate I'll only be able to last another month.

"After that I'll just stop by to see that the metal blind is still fully shut," he adds quietly.

At four o'clock in the afternoon, the brothers close the pharmacy, wave to the five neighbours sitting at Ahmad Barada's makeshift stall in the square, and get into the car that has come to collect them.

Barada, a 45-year-old electrician, watched his shop in a neighbouring district go up in flames a week ago after an artillery shell slammed onto it. The explosion killed one of his sons who was inside.

"I'm here now to sell what I've salvaged from the wreckage," he says, sitting behind the stall, which consists of a plank on a cart. "I have to earn to eat."

Light bulbs, plug sockets, cables and small electrical stoves are laid out in front of him. He picks up a collection of items. "I'll charge 35 pounds (50 cents) for these," he says.

"People here are hard up. Everyone with the means has escaped and gone to their families or their villages. We have nothing. No car, no petrol. Where can we go?"

There's a sharp bang as a shell slams into a building two streets away, followed by 30 seconds of concentrated machinegun fire.

People stop their conversations for a moment, then pick up again as the noise recedes and grey smoke descends.

A fruit and vegetable seller lays out his wares -- boxes of tomatoes, grapes, cucumbers. All the shops that once bustled with activity before the war are shut.

"The real problem is bread," laments Barada.

"There's a bakery nearby but they only have flour. You have to go farther afield for bread but it's dangerous. And what used to cost 15 pounds now costs 50."

[Image via Agence France-Presse]