A satellite image confirms that a temple in the ancient Syrian city of Palmyra has been destroyed, the United Nations says.

There had been earlier reports of an explosion at the Temple of Bel in Palmyra, which is held by militants from Islamic State (IS).

Syria's antiquities chief had earlier said the basic structure of the 2,000-year-old site was intact.

But UN satellite analysts Unosat say the imageshows almost nothing remains.

"Unfortunately, the images we acquired do show that the main building of the temple has been destroyed," Einar Bjorgo, Unosat's manager, told the BBC early on Tuesday.

He added that a set of columns nearby had also been destroyed.

On Monday, Maamoun Abdulkarim, the head of the Syrian Department of Antiquities and Museums, had said the Temple of Bel suffered a large explosion, but that he believed most of the site had remained intact.

Witnesses had struggled, however, to get close to the site to confirm the extent of the damage.

The Temple of Bel is considered the most important structure of its kind at the site

Palmyra, and the Temple of Bel within it, received 150,000 visitors a year before the war

Last week, it was confirmed that another site at Palmyra, the Baalshamin temple,had been blown up.

Unosat released satellite images on Monday showing the extent of the damage to Baalshamin, proving that parts were heavily damaged or completely destroyed.

IS militants seized control of Palmyra in May, sparking fears for the World Heritage site.

The world-famous Greco-Roman ruins are in the desert north-east of the Syrian capital, Damascus.