By Oliver Holmes
ALEPPO, Syrian (Reuters) - "Bomb, bomb, bomb!" shouted the rebel fighters in the midst of battle on the streets of Aleppo. Everyone crouched down and held their fingers in their ears. But the rusty foot-long metal container they rolled into a building hiding enemy Syrian army forces failed to explode.
"The batteries were dead and it didn't work," said Abu Furad, a rebel commander in aviator sunglasses, who still wears the Syrian army uniform he was issued before he defected to the rebel cause three months ago.
Desperately short of weapons and ammunition, Syrian rebels have set up factories producing a wide array of homemade bombs and grenades that they can take into battle against much better-armed government forces.
Abu Furad had another homemade explosive device in the pocket of his vest - a black metal tube with a small ceramic coffee cup attached to the top by a wire. The cup acts as a trigger like the pin of a grenade.
He pulled off the coffee cup, leaned around the corner and tossed the bomb towards the building where the soldiers lay. After a few seconds a loud blast shook the air.
In a farm complex outside Aleppo, rebels were cutting and welding metal to make bombs. On the floor of an outhouse, once used to house tractors and farming machinery, a dozen metal cylinders stood ready to be packed full of explosives.
"What we do is, when the Syrian army starts attacking the city, we'll go around and look for missiles that haven't exploded. We'll drill into the head and remove the TNT," said bomb maker Abu Ghagan, lifting a bent missile he says he found in a field.
He said he learnt his trade from the Internet.
"We are very short on proper explosive so we use a mix of fertilizer to make the rest," he added, walking round his factory at night to avoid drawing attention from neighboring farmers.
As a bomb-maker, Abu Ghagan is quiet and careful — he knows the army would pay good money to get the coordinates of a bomb factory so they can send their bomber jets.
Makeshift bombs can be detonated remotely using mobile phones. Abu Ghagan also has home-made missiles that he says can be propelled five km.
The meter-long missiles have a large head packed full of explosives with a detonator on the end, and fins to keep them flying in a straight line.
"These are good. We use them to fire into army barracks," he said.
Their lack of modern weapons is a common lament among rebels, who say that Western countries that have called for the downfall of President Bashar al-Assad need to do more to make that happen by giving them arms.
Western countries say they are supplying the rebels only with non-lethal equipment, like radios. Gulf states like Saudi Arabia and Qatar have spoken of the need to arm the rebels and are thought to have sent them guns and ammunition.
But whatever weapons are coming in, they are hardly arriving fast enough to match the government's vast arsenal.
At the start of the war, Syria's army had nearly 5,000 main battle tanks, a similar number of other armored vehicles, 3,500 pieces of artillery, 240 ground-attack jets, 85 fighters and more than 140 helicopters, according to the London-based International Institute of Strategic Studies.
Many rebels say they joined the fight using hunting shotguns and only later looted assault rifles from government soldiers killed in battle. Their homemade bombs show resourcefulness, but on the streets of Aleppo it was not clear how effective they were.
Shortly after Abu Furad threw his grenade into the house, the rebels came under a barrage of fire. Three mortar bombs hit the building across the street, less than 10 meters away.
Then the sound of tank tracks could be heard moving up the next street. The tank fired a shell which ripped through the building the rebels had been using for cover. Smoke filled the air and chunks of concrete rained down.
As the smoke dispersed the rebels looked around to see if their comrades were hurt. Then one fighter spotted something: a tank shell.
Determined, he ran into the street to pick up the unexploded shell, to be dismantled and repacked into a rebel bomb.
(Additional reporting by David Cutler, London Editorial Reference Unit; Editing by Peter Graff)