Founded toward the end of the 5th century A.D. as a humble market village, Timbuktu became an important intellectual and spiritual center under the country's Askia dynasty toward the end of the 15th century.
"Danger listing attempts to draw attention to problems with particular sites to improve their management," said UNESCO spokesperson Roni Amelan.
"Often, it can involve asking for international assistance or the sharing of expertise."
The World Heritage Committee's decision to add Timbuktu to the danger list reflects growing international concerns about the looting and destruction of its historical sites after the city was taken over earlier this year by the armed groups MLNA and Ansar Dine.
According to Voice of America, Ansar Dine said the shrines at Timbuktu are idolatrous and un-Islamic.
In June, UNESCO director-general Irina Bokova expressed dismay over reports that three sacred tombs at Timbuktu had been destroyed.
"There is no justification for such wanton destruction," Bokova said in a statement, "and I call on all parties engaged in the conflict to stop these terrible and irreversible acts."