Timbuktu - The UN's cultural wing has reported the destruction of precious mausoleums during an Islamist takeover of northern Mali to the International Criminal Court, its head said on a visit on Saturday to witness their reconstruction.Al-Qaeda-linked insurgents seized Timbuktu - around 1 000km northeast of Mali's capital Bamako - alongside the west African nation's other desert towns and cities in 2012.They wrecked 16 of its shrines to Muslim saints that date back to the ancient caravan city's 15th and 16th century golden age as an economic, intellectual and spiritual centre. "Unesco has involved the International Criminal Court with the destruction of the mausoleums," Irina Bokova, the organisation's general director, told reporters at the end of a visit to Timbuktu."Two months ago I met the prosecutor and I believe they are progressing rapidly, and I hope they will be ready to present the case before the ICC," she added, without giving details of what charges would be brought.Destroying cultural heritage a war crimeThe mausoleums are designated as World Heritage monuments by Unesco, and Bokova said destroying cultural heritage was considered a war crime under the UN's 1954 Hague Convention.The UN cultural body began rebuilding Timbuktu with the Malian government and other international organisations after a 2013 French-led military operation drove the jihadists out of the city.The reconstruction, which started last year, relies heavily on traditional building methods and cultural knowledge of the area, generating around 140 local jobs.The masons are using the local alhor stone, rice stalks and banco - a mixture of clay and straw - to rebuild 14 of the 16 mausoleums, destroyed along with thousands of manuscripts because the Islamists considered them to be idolatrous. "It is through the reconstruction of mausoleums that we can accompany the peace agreements and restore the identity of the city... We will also help renovate other riches of Timbuktu cultural heritage," Bokova told reporters.The mausoleums were constructed to pay homage to deceased saints who were regarded as pious, great humanists and scholars of their time. For the people of Timbuktu - dubbed the "city of 333 saints" - their destruction was an assault on Malian history and culture. Around 4 000 manuscripts were lost, stolen or burned, during the Islamist takeover, and 10 000 manuscripts were discovered in unsuitable storage conditions. But 370 000 of these priceless parchments were smuggled to Bamako in 2012 to protect them from the jihadists and archivists in Mali's capital are now painstakingly classifying and digitising them.The entire restoration project is expected to last four years and cost $11 million. So far $3 million has been collected with the support of the World Bank, the European Union, Switzerland and the US Agency for International Development.