Syrian rebels have unveiled their latest weapon in the fight against President Bashar Assad's forces.

The "Borkan" (Volcano) is an improvised multiple rocket launcher made out of a mechanical digger with four pipes attached it. It can fire four shells made out of gas canisters up to three kilometres.

The rebels do have an arsenal of conventional munitions – either captured from the Syrian army or supplied by sympathetic foreign countries. But there is also a thriving cottage industry making additional weapons out of whatever is available.

Some enterprising rebel groups have even built their own armoured vehicles, operated using video game controllers.

Lacking the resources of Assad's government forces, rebels have had to improvise weapons. Mortar shells are turned on lathes in factories and fired using a variety of improvised launchers. Homemade grenades are launched from giant catapults or customised shotguns.

In this gallery we look at some of the homemade munitions used by the Free Syrian Army.