The international community must strive for a suitable response to cultural destruction as shown by the deliberate wrecking of ancient sites in Syria and Mali by ultra-radicals, the head of the U.N.’s cultural organization said.

Irina Bokova, director general of the United Nations Educational Scientific and Cultural Organization (UNESCO) said it took some time for authorities to respond to the significance of what extremist groups were doing.

In an interview with Reuters in Kabul, Bokova spoke of how such groups typically seek to clear the ground to persecute minorities and consolidate power by “cultural cleansing”, wiping off traces of other cultures.

Fifteen years ago, the Afghan Taliban provided one of the most notorious recent examples when it blew up two giant ancient statues of the Buddha in 2001, decreeing they were un-Islamic.

But the demolition of medieval shrines in Timbuktu by Malian jihadists in 2012 and then the destruction by ISIS militants in Syria of parts of the ancient city of Palmyra last year brought the danger home, said Bokova, a former acting foreign minister of Bulgaria who is among candidates to become U.N. Secretary General later this year.

“I have to say that at the beginning of the Syrian crisis we were not taken that seriously when we started denouncing this destruction,” said Bokova.

“Now I think people see what the danger is. I know it is not easy but now everybody takes seriously the destruction of heritage and culture as part of this extremist strategy. Probably the most visible embodiment of this, even,” she said.

However, she said, the world was still wrestling with how to deal with the problem, which had driven matters once the preserve of museums firmly into the strategic sphere.

“I think it is a new type of phenomenon that is emerging and we are seeking a response.”

Last year’s U.N. Security Council Resolution 2199, which specifically targets the illegal trade in antiquities alongside oil and hostages as a means of shutting off funding to groups like ISIS and Al Qaeda, was one example, she said.

The trial of the radical Ahmad al-Faqi al-Mahdi in the International Criminal Court over the destruction of the religious sites in Timbuktu was another.

Bokova on Friday signed a culture trust fund agreement with the Afghan government, aimed at shoring up efforts to promote cultural industries and restate the importance of cultural and national identity.

How far such programs can hope to succeed in countries worn-out by competing visions of social, religious and cultural identity remains open.

In Afghanistan, a country with more than 30 languages and multiple different ethnicities which has undergone civil war and conflict for most of the past four decades, the notion of cultural identity remains particularly fluid.

“I don’t say it’s easy,” Bokova said. “But it is necessary and we have to start from somewhere.”