A huge convoy of 100 retired ambulances that set off from the UK in April has arrived in Syria, where they are already being put to use.

Volunteers for the charity coalition Unity Convoy drove the decommissioned vehicles across five countries, arriving at the Syrian border last week, in what is thought to be the biggest aid convoy of its kind to make such a long journey.

The vehicles were transferred to rebel-held Idlib province, where they were delivered to local hospitals.

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The fully equipped units were called into use within hours of arrival after an explosion hit a marketplace in Idlib city on 20 June.

“As soon as we received the Unity Convoy Ambulances, we heard an explosion nearby. The ambulance response team immediately set off to the area of the incident,” Dr Moustafa of Idlib’s Health Directorate said in a statement.

The five UK charities that organised the Unity Convoy say that one ambulance can save up to 43 lives a month.

“The British public can be proud of their contribution to the humanitarian effort in Syria over the past years. This is yet another example of that contribution,” Unity Convoy spokesperson Alim Sharmas said in relation to the explosion.

No claim of responsibility was made for the incident, which injured several people and killed three.

Syrians make fuel from plastic waste Show all 8 1 /8 Syrians make fuel from plastic waste Syrians make fuel from plastic waste Sifting through plastic: the workshop uses plastic from bottles and other waste materials to produce liquid and gas fuels. The liquid is refined into gasoline, diesel and benzene fuels, which in turn are sold for domestic and commercial use Reuters Syrians make fuel from plastic waste Khodor, 20, at the workshop in the rebel-held and besieged neighbourhood of Douma, Damascus Reuters Syrians make fuel from plastic waste Back to basics: a man checks the heat of a pipe pouring with fuel Reuters Syrians make fuel from plastic waste Khodor, 20, must keep an eye on the burning plastic inside the workshop in Douma Reuters Syrians make fuel from plastic waste A young man takes a container of the locally made fuel, which can be used for domestic heating and on farms and bakeries Reuters Syrians make fuel from plastic waste Abu Fahad on a rest break with his colleagues inside the workshop, where the air is heavy with toxic fumes Reuters Syrians make fuel from plastic waste Fuel drips into a container at the workshop. Most locals are glad of the family-run business, which has restored a degree of normality to the region Reuters Syrians make fuel from plastic waste Khodor extracts fuel from plastic in the workshop Reuters

An agreement declaring the establishment of four 'safe zones' across Syria, including Idlib, was negotiated by Russia, Iran and Turkey last month and is mostly holding.

Several hospitals and medical centres across the region have already been bombed out of operation, however, and face equipment, medicine and staff shortages. Small pockets of ground fighting and mortar shelling are ongoing between al-Qaeda affiliated rebel forces, US-backed rebels, and forces supportive of Syrian President Bashar al-Assad’s government.

The Unity Convoy was born earlier this year after the targeting of hospitals by Syrian and Russian air strikes during the fall of Aleppo in late 2016.

Up to 100 ambulance units were lost in the bombing, contributing to the death toll as emergency workers struggled to care for casualties in civilian transport.

The British charities involved managed to raise £500,00 in just three months to get the idea off the ground and send the ambulances on their way to Syria.

In the past the UK’s Charity Commission regulator has warned against sending convoys without government or UN co-ordinated delivery, fearing they could be used for “non charitable purposes.”