Bashar al-Jaafari, Syrian chief negotiator and Ambassador of the Permanent Representative Mission of Syria to the UN New York, center, arrives for another round of negotiations with UN Special Envoy for Syria Staffan de Mistura at the European headquarters of the United Nations in Geneva, Switzerland, Tuesday, May 16, 2017. (Salvatore Di Nolfi/Keystone via AP)
Bashar al-Jaafari, Syrian chief negotiator and Ambassador of the Permanent Representative Mission of Syria to the UN New York, center, arrives for another round of negotiations with UN Special Envoy for Syria Staffan de Mistura at the European headquarters of the United Nations in Geneva, Switzerland, Tuesday, May 16, 2017. (Salvatore Di Nolfi/Keystone via AP) Credit: SALVATORE DI NOLFI

Beirut — Syria on Tuesday rejected U.S. accusations it carried out mass killings at a prison near Damascus and then burned the victims’ bodies in a crematorium, describing the allegations as “lies” and “fabrications.”

The allegations are a “new Hollywood plot” to justify U.S. intervention in Syria, Syria’s Foreign Ministry said, noting what it called a U.S. track record of using false claims as a pretext for military aggression.

The State Department said on Monday it believes that about 50 detainees are hanged each day at the Saydnaya military prison, a 45-minute drive north of Damascus.

Many of the bodies are then burned in the crematorium “to cover up the extent of mass murders taking place,” said Stuart Jones, the top U.S. diplomat for the Middle East. He accused the government of President Bashar Assad of sinking “to a new level of depravity.”

The Syrian government forcefully denied it.

“The U.S. administration’s accusations against the Syrian government of a so-called crematorium in Saydnaya prison, in addition to the broken record about the use of barrel bombs and chemical weapons, are categorically false,” the Foreign Ministry said.

The new allegation comes at a time when the Trump administration is weighing its options in Syria, where an estimated 400,000 have been killed and half the population displaced by the 6-year-old civil war.

The U.S. Treasury Department said it has frozen any assets that five Syrian people and five Syrian companies may have in U.S. jurisdictions and has barred Americans from conducting any financial transactions with them, citing Syria’s “relentless attacks on civilians.”

Western monitors and watchdog groups say they have accumulated evidence of mass killings in Syrian prisons, though there have not been any substantiated allegations so far of the use of a crematorium.

The State Department released commercial satellite photos showing what it described as a building in the prison complex that was modified to support the crematorium. The photos, taken over several years starting in 2013, do not prove the building is a crematorium, but show construction consistent with such a facility.

The revelations echoed a February report by Amnesty International that said Syria’s military police hanged as many as 13,000 people in four years before removing bodies by the truckload for burial in mass graves.

U.N. spokesman Stephane Dujarric said on Tuesday that the world body cannot independently verify the U.S. report, saying Damascus has “systematically rejected” repeated requests to visit prisons and detention centers where thousands of prisoners are believed to be subjected to cruel treatment.

Also on Tuesday, President Donald Trump met Turkish President Recep Tayyip Erdogan at the White House for talks on the conflict, refugee crisis and the fight against the Islamic State group.

Last month, the U.S. fired cruise missiles on a government air base after accusing Assad’s military of killing scores of civilians with a sarin-like nerve agent.