THESE are the damning satellite images which reportedly prove that mass killings are being covered up inside a notorious slaughterhouse prison.

The US said the images show the Syrian Government has installed a crematorium inside the notorious Saydnaya military prison to destroy evidence that thousands have been executed there.

Damning new claims by the US include satellite images which appear to show snow melting on the roof of the facility.

Stuart Jones, acting assistant secretary for the State Department Bureau of Near Eastern Affairs, said this supported evidence that a crematorium is being used to destroy thousands of bodies.

“Beginning in 2013, the Syrian regime modified a building within the Saydnaya complex to support what we believe is a crematorium,” he said, referring to a military jail north of Damascus.

“Although the regime’s many atrocities are well documented, we believe that the building of a crematorium is an effort to cover up the extent of the mass murders taking place in Saydnaya.” Jones said Washington’s information came from credible humanitarian agencies and from the US “intelligence community” and that as many as 50 people per day are thought to be hanged at Saydnaya.

He did not give an official estimate for the total number killed, but cited an Amnesty International report that between 5,000 and 11,000 had died between 2011 and 2015 in the prison.

President Bashar al-Assad’s Syrian regime, he alleged, had detained between 65,000 and 117,000 people over the same period.

The latest satellite photograph presented by Jones dated to January 2015, more than two years ago, and it was not immediately clear why the United States waited to present its evidence

Mr Jones also called on Assad’s supporters to use their influence to stop Assad’s continued atrocities.

“The United States is on record, has stated many times, that we are appalled by the atrocities that have been carried out by the Syrian regime,” Mr Jones said.

“And these atrocities have been carried out seemingly with the unconditional support from Russia and Iran.

“Russia must now, with great urgency, exercise its influence over the Syrian regime to guarantee that horrific violations stop now.”

The US said the satellite images as well as heavy-duty ventilation systems on the structure, appear to support earlier claims by human rights groups that Saydnaya is an execution centre.

‘HUMAN SLAUGTERHOUSE’

This wouldn’t be the first time brutal allegations of mass killings have been aired about the prison, located 45 minutes outside Damascus.

Saydnaya Military Prison made global headlines in February following a report by human rights group Amnesty International which claimed thousands of Syrians have been hanged there following a crackdown on dissent.

Its report Human Slaughterhouse alleges thousands of people have been hanged at the prison just 45 minutes outside the capital of Damascus.

Based on interviews with 84 former detainees, judges, guards and human rights experts from the Saydnaya, Amnesty said up to 13,000 people were systematically killed in groups of as many 50 twice a week over the last five years.

The Amnesty report said the killings of mostly civilians were sanctioned at the “highest levels” of the Syrian government.

Chillingly the report also detailed how prisoners are moved from the cells in the middle of the night believing they are being transferred. Instead they are reportedly hanged in the prison grounds.

‘DROP IN THE OCEAN’

Mr Jones’ warning came as UN-mediated peace talks between Damascus and the Syrian opposition were about to resume in Geneva, and appeared aimed at maintaining pressure on Assad’s backers.

The head of the opposition delegation to the talks welcomed the US statement, but said it had come too late.

“This is but a drop in the ocean. What happens in the regime’s prisons is much uglier than this,” Nasr al-Hariri said.

“The time has come for the world — chiefly the US — to act to halt these human rights violations.”

DAMNING EVIDENCE

Mr Jones refused to confirm whether the US would take military action over the crematorium discovery.

But he said the US would “bring evidence forward to the international community”, CNN reported.

More than 400,000 have been killed since the Syrian conflict began in 2011 and Mr Jones said the Syrian Government’s use of chemical weapons, air strikes and use of abuse and torture has been widely reported.

The US has not yet shown the new evidence to Russia, which had previously backed Assad who denied carrying out chemical attacks on civilians.

Most recently, Russia blamed Syrian rebels for a chemical gas attack carried out in the province of Idlib, which left more than 90 people dead, including 30 children.

The US said it believed the chemical agent sarin was used in the attack that the attack was “almost certainly” carried out by forces loyal to President Bashar al-Assad.

The Syrian government “categorically rejected” claims that it was responsible for the attack in Khan Sheikhun, claiming it does not possess chemical weapons.

debra.killalea@news.com.au