Palmyra 'not entirely ruined'
The ruins were inspected by experts from UNESCO who clarified the findings on Wednesday.
The UN cultural agency visited the site to analyse the damage caused during the year-long IS occupation.
"Despite the destruction of several iconic edifices, the archaeological site of Palmyra retains a large part of its integrity and authenticity," a statement said.
Both the Palmyra museum and the archaeological site were inspected during the mission.
"They took stock of considerable damage to the museum where they found that most of those statues and sarcophagi that were too large to be removed for safekeeping were defaced, smashed, their heads severed, their fragments left lying on the ground," UNESCO said in a statement.
But significant parts of the world heritage site were totally destroyed, the mission confirmed.
"They observed the destruction of the triumphal arch and Temple of Baal Shamin, which was smashed to smithereens," said the statement.
During their 10-month rule over the city, the militants executed hundreds of civilians and blew up some of Palmyra's most beautiful temples and funerary towers in the old city.
The findings are expected to be put into writing in a report to be submitted at the world heritage committee's annual meeting in July in Turkey.
The UN cultural agency has vowed to send another mission to examine Syrian heritage sites in greater detail.
Palmyra, north-east of Damascus, contains the monumental ruins of a great city that was once a crucial hub for trade, culture and tourism.
The ancient ruins were overrun by the Islamic State group last year but was recaptured by Russian-backed government forces last month, in a crucial and strategic defeat for the militants.