"I am profoundly shocked by the ferocity that has marked the latest round of destruction of Timbuktu's mausoleums," Bokova said.
A news release from the United Nations Tuesday said at least three mausoleums in Mali were attacked Sunday. Three others were destroyed in July.
Islamist groups, that claim the sites are against Islamic tradition that forbids veneration of saints, have threatened to tear down additional mausoleums.
The mausoleums, shrines hundreds of year old that honor Sufi Muslim figures, have been designated part of the U.N. World Heritage site.
After the vandalism, the United Nations said it conducted two emergency missions and set up a fund for rehabilitation of Mali's cultural heritage.
"I call on the whole of the international community to act, as a matter of urgency, and take the measures necessary to guarantee the protection of this heritage, which is such an important part of Mali's cultural identity and of humanity's history," Bokova said.
The U.N. Educational, Scientific and Cultural Organization reports that Timbuktu was an intellectual and cultural capital in the 15th and 16th centuries.
Mali has been racked by violence in recent months with much of the fighting blamed on al-Qaida in the Islamic Maghreb