UNITED NATIONS — A team of experts led by UNESCO said Friday it has found far more serious damage to Mali’s cultural heritage in the fabled city of Timbuktu than initially estimated, with 16 mausoleums totally destroyed and over 4,000 ancient manuscripts lost.

Lazare Eloundou Assomo of UNESCO’s World Heritage Center, who led the mission, said a visit to the damaged and destroyed sites on Thursday revealed that the destruction by Islamist rebels who occupied Timbuktu and the rest of the north until early this year “is even more alarming than we thought.”