A World Heritage Site in Timbuktu in northern Mali has been attacked and burned. The act on Sunday threatens to raise tensions that have been building between the people in Timbuktu and the Islamists who occupied the city in April."A new member of the Ansar Dine group came to Timbuktu and went to the tomb of Sidi Mahmoud Ben Amar on Friday to tell the faithful praying there that the saints” should not be adored, said Sanda Ould Boumama, a spokesman for Ansar Dine.The tomb for Sidi Mahmoud Ben Amar is among 16 cemeteries and mausoleums classified as UNESCO World Heritage Sites in Timbuktu, according to a UNESCO website. The city has 333 tombs for saints. Timbuktu also has mosques classified as World Heritage Sites.Boumama refused to say whether Ansar Dine supported the act or not, and that since the man was new to the group the act must first be investigated.Residents at the scene had earlier described the offender as a member of al-Qaeda in the Islamic Maghreb (AQIM). Diplomats in Bamako have said Ansar Dine has links with AQIM.Mahamane Cisse and other witnesses who went to pray at the tomb said that a Mauritanian member of AQIM and some members of his group on Friday tore off the doors of the tomb and burned some items, including a mosquito net on the tomb.World Heritage SiteAghaly Yattara said that one of worshippers at the tomb tried to stop the destruction, but men bound him and put him in the back of their car. He said that they eventually released the man.Religious leaders  called on the Islamic High Council of Mali to denounce this act, and young residents of Timbuktu said they will stage sit-ins in the coming days so that other tombs of saints are not desecrated, said Kader Kalil Ascofare, the director of a local radio station. Tuareg separatist fighters and Islamists took advantage of the chaos caused by the coup in Bamako in late March to quickly advance and capture the three main towns in the north of Mali. Mali government forces fled south without putting up any major resistance.Ansar Dine, Arabic for Supporters of Islam, was formed at the end of last year and joined the Tuareg fighter group in chasing government forces out of the north, but Ansar Dine now says that it is against north Mali becoming independent.