Syria's head of antiquities was quoted as saying that Islamic State militants have destroyed Palmyra's ancient temple of Baalshamin.

The temple was blown up on Sunday according to Syrian officials. The UK -based Syrian Observatory for Human Rights (SOHR) however reported that it happened a month ago.

IS took control of Palmyra in May, sparking fears for the site considered as one of the ancient world's most important cultural centres.

The ancient city, which is a Unesco World Heritage site, is famed for its well-preserved Greco-Roman ruins, and the Baalshamin temple, built nearly 2,000 years ago, is one of the city's best-known buildings.

The Islamic State group has destroyed several ancient sites in Iraq. The militants believe any shrines or statues implying the existence of another deity are sacrilege and idolatry, and should be destroyed.

IS "placed a large quantity of explosives in the temple of Baalshamin today [Sunday] and then blew it up causing much damage to the temple," Syrian antiquities chief Maamoun Abdulkarim told a news source.

"The cella (inner area of the temple) was destroyed and the columns around collapsed," he said.