said their fighters were 'more deserving' of the organs

ISIS doctors are harvesting organs and draining the blood of healthy captives', a former prisoner has revealed.

Abo Rida said surgeons for the terror group removed kidneys and corneas from prisoners and treated them as 'blood banks' for wounded fighters.

He also revealed how those not strong enough for organ donation were forced to endure daily torture at the hands of barbaric IS militants in Raqqa, Syria.

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A former prisoner has revealed that ISIS doctors are harvesting organs and draining the blood of healthy captives'

A former captive revealed that kidneys and corneas had been taken from prisoners for injured jihadists

Rida, who managed to escape the jihadists clutches, said the situation inside their make-shift prisons is getting 'worse day after day.'

He revealed that healthy and strong prisoners were 'taken special care' of by the militants and escaped day-long torture sessions.

'ISIS was using them as a blood bank to withdraw blood when they need it for injured members,' he said.

But, Rida revealed that doctors were also harvesting organs from their captives.

'They moved organs such as kidneys and corneas from the prisoners.' he told a website run by anti-ISIS activists.

He said the terror group argued that 'the fate of these prisoners (was) inevitable death' and the jihadists were 'more deserving' of the organs.

Another captive told how the doctors would normally come looking for blood shortly after inmates would hear explosions.

Other times, they would not hear anything and assume IS fighters had been involved in bloody battles.

Rida told how those held captive with him endured 'all kinds of torture' after being accused of crimes including insulting Allah, trying to topple the jihadists, and being part of the free army.

He said the torture would last all day and there was no 'specific time' for it to start and finish.

Four months ago he managed to escape during the confusion and dust after the prison suffered a direct hit during a counter terrorism raid.

'Not many of us could escape because ISIS members fired at us,' he said.

Rida was one of only four who made it to safety.

This is not the first time the terror group has been accused of harvesting organs.

See more of the latest news and updates on Islamic State and the war in Syria

Those captives not deemed strong enough by Islamic State are forced to endure brutal torture sessions

Abo Rida, who managed to escape the militants, told how the conditions of IS captives were getting worse each day

Earlier this year the UN were urged to investigate Islamic State terrorists' bloody trade in human organs

Earlier this year the United Nations were urged to investigate Islamic State terrorists' bloody trade in human organs in Iraq.

Iraqi ambassador Mohamed Alhakim claimed that dozens of bodies with surgical incisions and missing body parts have been found in shallow mass graves near Mosul

They were also said to have murdered doctors who refused to take part in organ harvesting.