BONN, Germany - The United Nations Educational, Scientific and Cultural Organization (UNESCO) completed its annual update of the List of World Heritage in Danger here on Thursday and added three sites in conflicted areas in Yemen and Iraq into the list.

UNESCO's World Heritage Committee, which started its 2015 annual meeting here on June 28, said all the three sites, the Old City of Sana'a and the Old Walled City of Shibam in Yemen and Hatra in Iraq, were listed as endangered due to damages or threat from the ongoing armed conflicts in the two countries.

According to the committee, the Old City of Sana'a in Yemen sustained "serious damage" due to the conflicts. "The majority of the colorful, decorated doors and window panes characteristics of the city's domestic architecture have been shattered or damaged," it said.

The Old City of Sana'a has been inhabited for more than 2,500 years and became a major center for the propagation of Islam in the 7th and 8th century. Its religious and political heritage can be seen in 103 mosques, 14 hammams and over 6,000 houses which were built before the 11th century.(Xinhua)