Satellite images have confirmed the destruction of another famed temple in Syria's Palmyra, the United Nations says.

"We can confirm destruction of the main building of the Temple of Bel as well as a row of columns in its immediate vicinity," the UN training and research agency UNITAR said, providing satellite images from before and after a powerful blast in the ruins of the ancient city on Sunday.

The blast had already raised fears on Monday that the Islamic State (IS) group had damaged another of the Middle East's most treasured heritage sites.

UNITAR said its satellite program put to rest any doubts that the 2,000-year-old Temple of Bel had been destroyed in the blast.

What is the Temple of Bel? The Temple of Bel, also referred to as the Sanctuary of Bel, is among the best preserved of the ruins in Palmyra

The Temple of Bel, also referred to as the Sanctuary of Bel, is among the best preserved of the ruins in Palmyra While little is known about Palmyra's gods, Bel is assumed to be the most important, the equivalent of the Greek Zeus or Roman Jupiter

While little is known about Palmyra's gods, Bel is assumed to be the most important, the equivalent of the Greek Zeus or Roman Jupiter The temple, a mixture of Near Eastern and Roman architecture, is believed to be nearly 2,000 years old, dating back to AD32

A shot taken on August 27 clearly shows an erect, rectangular structure surrounded by columns, while a shot taken on Monday showed there was little left besides a few columns in the very outer edges of the site.

IS already destroyed the smaller Baal Shamin temple at Palmyra last week, confirming the worst fears about their intentions for the site, which they seized from Syrian regime forces in May.

UNITAR on Friday also presented satellite images confirming the destruction of the Baal Shamin temple, which the UN's cultural agency UNESCO called a "war crime".

The jihadists have carried out a sustained campaign of destruction against heritage sites in areas under their control in Syria and Iraq, and in mid-August beheaded the 82-year-old former antiquities chief in Palmyra.

The extremist group's interpretation of Islam considers statues and grave markers to be idolatrous, but it has also been accused of destroying heritage sites to loot items for the black market and to gain publicity.

Known as the "Pearl of the Desert", Palmyra, which means City of Palms, is 210 kilometres north-east of Damascus.

More than 150,000 tourists were visiting Palmyra every year before the Syrian conflict erupted 2011.

Before the arrival of Christianity in the second century, Palmyra worshipped the Semitic god Bel, along with the sun god Yarhibol and lunar god Aglibol.

Syria's antiquities chief Maamoun Abdulkarim described the Temple of Bel as Palmyra's most important site, and also the most important temple in the Middle East along side Baalbek in Lebanon.

Construction on the temple began in 32 BC and ended in the second century, and it later served as both a church and a mosque.

The Temple of Bel was described as one of the most important temples in the Middle East. ( Reuters: Omar Sanadiki )

AFP