The governor of the historic Iranian city of Isfahan has accused the US and Israel of a “declaration of war on a civilization” as heritage sites across the country suffer damage in their bombing campaign.

The most serious confirmed damage to date has been to Tehran’s Golestan palace, dating back to the 14th century, and the 17th-century Chehel Sotoon palace in Isfahan.

Judging from videos and public statements, neither historic building was hit by a missile directly but the shock wave from nearby blasts and possibly some missile debris, shattered glass and brought down tiles and masonry.

Video from the scene showed that the Golestan palace’s celebrated hall of mirrors had been shattered with shards of intricate mirrorwork scattered across its floor.

The palace is a world heritage site under the protection of the UN’s cultural body Unesco, which issued a statement of concern after it was damaged on 2 March, saying it had “communicated to all parties concerned the geographical coordinates of sites on the world heritage list”.

In the past few days, there have been major explosions in the centre of Isfahan, Iran’s capital in three historical eras, where much of the architecture dates back to the Safavid dynasty era, from the 16th to 18th centuries.

The Chehel Sotoon palace suffered the worst impact but broken windows and doors, as well as dislodged tilework, have been reported in the Ali Qapu palace and several mosques around the vast Naqsh-e Jahan square. Videos filmed by residents from inside the square showed plumes of smoke rising from nearby airstrikes.

The Isfahan governor, Mehdi Jamalinejad, said the damage had been inflicted even after coordinates of the historic sites had been circulated among the warring parties and after blue shield signs – denoting historical treasures under the 1954 Hague convention for the protection of cultural objects in war – had been put on the roofs of important buildings.

“Isfahan is not an ordinary city, it’s a museum without a roof,” Jamalinejad said in a speech posted on social media.

“In none of the previous eras, not in the Afghan wars, not in the Moghul conquest, not even during the ‘sacred defence’ [the 1980-88 Iran-Iraq war] was this ever done,” the governor said.

“This is a declaration of war on a civilisation,” he added. “An enemy that has no culture pays no heed to symbols of culture. A country that has no history has no respect for signs of history. A country that has no identity sets no value for identity.”

An Iranian geologist who worked in Isfahan for many years said in a message forwarded to the Guardian that the ancient capital was particularly vulnerable.

“Isfahan has long been attacked from below, by land subsidence that is destroying the Safavid-era structures, and now from the above, by the Americans,” the geologist said. “Isfahan seems to have fewer friends than ever today.”