ISIS militants have reportedly used dynamite to destroy an ancient temple situated in the Syrian archaeological site of Palmyra.

The Baalshamin temple had stood at the site for nearly 2,000 years and was considered one of the best preserved temple on the site.

The destruction has been described as an 'immense loss for the Syrian people and for humanity' by the UN's cultural watchdog Unesco, who also labelled it a 'war crime'.

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Activists from the Britain-based Syrian Observatory for Human Rights confirmed that the temple of Baalshamin (pictured before its destuction) had been destroyed, suggesting it may have been dynamited one month ago

Destroyed: The beautifully preserved temple (pictured) had had stood at the archeological site of Palmyra for nearly 2,000 years

Meaning 'Lord of Heaven', the temple was dedicated to the ancient pagan god of Baal.

One witness, who goes by the name Nasser al-Thaer, said ISIS militants had been laying explosives around the temple for more than a month.

He said he feared for the other ancient sites in Palmyra but that no explosives have been placed around them.

Activists from the Britain-based Syrian Observatory for Human Rights also confirmed that the temple of Baalshamin had been destroyed.

The news comes after ISIS used a bulldozer to demolish the 1,500-year-old Mar Elian Monastery, a national Syrian treasure, which has stood in Al-Qaryatayn since 432 AD.

ISIS supporters shared the pictures online and praised them for destroying the building because God 'was not worshipped there'.

The also extremists captured more than 200 people when it seized Al-Qaryatayn on August 6 and took 100 of them to the group's de-facto capital of Raqqa.

Palmyra used to be one of Syria's most popular tourist attractions and was well known for its rich history

Desecrated: An ISIS fighters stands inside the ruins of the Mar Elian Monastery, which it has now destroyed

Seized: ISIS conquered the village of Al-Qaryatayn, where Mar Elian (pictured) has stood since 432 AD, on August 6

Inhumane: Images shared by Islamic State's Dishmaq media office in Syria showed the bulldozer ploughing into the ancient structure

The desecrated Assyrian monastery took its name from Saint Elian, who was martyred after refusing to denounce his Christianity at the hands of his father, a Roman officer. Many 'miracles' were attributed to St Elian, who was a doctor.

The church was built on the spot where he died and his remains still rest in a small sarcophagus in a small chapel near its main crypt.

When Mar Elian was renovated in 1969, the plaster which lined the walls was removed to reveal stunning murals of Jesus, Mary and prophets dating back to the 6th Century.

An Italian Jesuit priest, Father Paolo Dall'Oglio, began work to renovate the church one more time around ten years ago.

He was kidnapped by ISIS In July 2013 and although his fate is unknown, sources of the Assyrian International News Agency say he was killed by a Saudi-national upon capture.

Of the 230 people who were kidnapped by ISIS in Al-Qaryatayn a few weeks ago, the Syrian Observatory for Human Rights claims some were taken from a church.

Rami Abdulrahman, the head of the Observatory, told MailOnline that more than 100 of them - which may include Christians - have now been taken to ISIS's war-ravaged capital of Raqqa.

How it was: The monastery was renovated around ten years ago by Father Paolo Dall'Oglio who was kidnapped by ISIS in July 2013

Historic: The Assyrian monastery (pictured) took its name from Saint Elian, who was martyred after refusing to denounce his Christianity at the hands of his father, a Roman officer

Destruction: Shocking images show ISIS soldiers using a bulldozer to demolish 1,500-year-old church in Syria

Hazardous: The Feast of St Elian is usually attracts large numbers of pilgrims every year, but the site became too dangerous to visit since ISIS seized Al-Qaryatayn

Kidnapped: An Italian Jesuit priest, Father Paolo Dall'Oglio (pictured), who renovated the church around 10 years ago was abducted by ISIS in 2013

Founder: The church was built on the spot where St Elian died and his remains still rest in a small sarcophagus (pictured) in a small chapel near its main crypt

These latest acts of barbarity come after ISIS butchered one of Syria's most respected archaeologists because he refused to reveal the location of gold and priceless artefacts in the ancient city of Palmyra.

Khaled Assad, 82, was held hostage by ISIS for over a month before he was beheaded.

A Christian group said the abductions were the latest in a string of events that targeted their community, one of the oldest Christian populations in the Middle East.

ISIS has also destroyed dozens of churches and ancient archaeological sites in the past year.

The group sparked global outrage when its militants were filmed destroying a collection of priceless statues and structures inside a Mosul museum.

It later turned out that most of the 3,000-year-old sculptures were worthless were replicas of the real artefacts which are housed safely in the capital Baghdad.

After the footage was released in February, Mosul's exiled governor confirmed the vast majority were fakes but at least two of the destroyed structures were authentic.

Atheel Nuafi told Saudi-based Al Arabiya: 'One is a Winged Bull and the other was the God of Rozhan.'

The Winged Bull, which was seen being smashed by sledgehammers, was supposedly the same one which stood at the gates of Nineveh in the 7th century BC.

Killed: Renowned archaeologist, Khaled Assad (pictured), 82, was held hostage by ISIS for over a month before he was beheaded

Fake: Most of the 3,000-year-old sculptures destroyed during an ISIS rampage through a Mosul museum were worthless replicas of the real artefacts which are housed safely in the capital Baghdad

Gone: The Winged Bull (pictured), which was seen being smashed by sledgehammers, was supposedly the same one which stood at the gates of Nineveh in the 7th century BC.

It was seen as a 'very important locally' because it was one of the few ancient objects that had not left the country or gone to Baghdad.

In April, footage showed ISIS using sledgehammers and barrel bombs to demolish the Iraqi city of Nimrud - near Mosul - which dates back to 13th Century BC.

Militants hammered away 3,000-year-old sculptures and carved stone slabs before bulldozing and exploding the ruins.

One fanatic said in the video: 'God has honoured us in the Islamic State to remove all of these idols and statutes worshipped instead of Allah in the past days.'

Another vowed that 'whenever we seize a piece of land, we will remove signs of idolatry and spread monotheism'.

Just weeks earlier the terror group took apart the historic Iraqi city of Hatra using AK-47 rifles and hammers.

Another video showed the extremists smashing shrines and statues in the 2,000-year-old city which was awarded UNESCO World Heritage status in 1985.

Barbaric: Footage from April showed ISIS using sledgehammers and barrel bombs to demolish the Iraqi city of Nimrud (pictured) which dates back to the 13th Century

Vile: Militants hammered away 3,000-year-old sculptures and carved stone slabs before bulldozing and exploding the ruins (pictured)

Again, one jihadi stared down the camera lens and declared that they had destroyed the site because it is being 'worshipped'.

In June, the group blew up two mausoleums in the Syrian city of Palmyra which it conquered a month earlier.

They even exploded the tombs of two descendants of the Prophet Mohammed, which it claims are a 'distraction', Syria's antiquities director confirmed.

Maamoun Abdulkarim said at the time that ISIS had destroyed more than 50 mausoleums, which were between 100 and 200-years-old in the north-east regions it controls.