Seven UN workers and 4 Afghans were killed in as an angry mob stormed a UN office in northern Afghan city of Mazar-e- Sharif following a protest against the reported burning of a Quran in the US a couple of days ago.

The protest demonstration was launched by locals after Friday congregation to condemn the reported burning of Quran by a priest couple of days ago in the United States, but unfortunately some elements with vicious designs availing opportunity attacked the compound of UN office

Last year Terry Jones, a US fundamentalist Christian leader, did threaten to burn copies of the Muslim holy book. He backed down after warnings that Islamic opinion around the world could be inflamed and the lives of US troops in Afghanistan and Iraq endangered. But on March 21, 2011, Wayne Sapp set light to a Qur'an with Jones standing by.

The incident has occurred a week after the Afghan president, Hamid Karzai, announced that Mazar-e-Sharif would be one of the first areas of the country to be transferred from NATO to Afghan government security control.

The killing of United Nations workers during an anti-Quran burning protest in the northern Afghan province of Balkh was denounced by NATO Secretary General Anders Fogh Rasmussen on Friday.

"I strongly condemn the attack that took place on the UN compound in Mazar-e-Sharif today, in which a number of UN staff were killed. The victims of these attacks were devoted to helping the Afghan people build better lives. In targeting them, the attackers have demonstrated an appalling disregard for what the UN and the entire international community are trying to do for the benefit of all Afghans," Rasmussen said.