The images, posted on social media by supporters of the group, showed militants carrying barrels of explosives, and laying them inside the temple.
Other smaller wired cans lay around the temple walls and columns. Then an image shows a grey plume of smoke rising above the temple from a distance, and then an image of the temple reduced to a pile of rocks.
One caption read: "The complete destruction of the pagan Baalshamin temple."
The images also corresponded to prior AP reporting. A resident of Palmyra had told the AP the temple was destroyed on Sunday, a month after the group's militants booby-trapped it with explosives.
The UN cultural agency UNESCO yesterday called the destruction of the temple a war crime.
The temple, a structure of giant stone blocks several stories high fronted by six towering columns, was dedicated to a god of storm and rain, the name means literally "Lord of the Heavens."
The Islamic State group, which has imposed a violent interpretation of Islamic law across its self-declared "caliphate" straddling Syria and Iraq, says such ancient relics promote idolatry.
It already has blown up several sites in neighbouring Iraq, and it is also believed to sell looted antiquities. The group had seized control of Palmyra, in the central deserts of Syria, in May.
