Eleven people, including eight UN employees, killed in attack on organization’s headquarters in northern city of Mazer-i-Sharif

Eleven people, including eight UN employees, were killed Friday in an attack on the organization's headquarters in the northern Afghan city of Mazar-i-Sharif as demonstrators were protesting at the burning of the Koran by a US pastor.

"In total, 11 people were killed - three foreign members of the UN, five Nepalese United Nations guards and three (Afghan) protesters," General Mohammad Daud Daud, a senior officer in the northern region told AFP.

A UN spokesman in New York confirmed only that there had been an unspecified number of deaths but if the toll is confirmed the attack would appear to be the deadliest on the UN in Afghanistan since the US invasion of 2001.

Mazar-i-Sharif is one of seven areas chosen by President Hamid Karzai and the international coalition to launch a process called "transition". Foreign forces will pass on the responsibility for security from July 1 to Afghan forces.

Ahead of Friday's violence, Afghanistan had condemned the disrespectful and abhorrent burning of the Koran by evangelical preacher Pastor Wayne Sapp in a Florida church, calling it an effort to incite tension between religions.

President Hamid Karzai called on the United States to bring those responsible for the burning of the Islamic holy book on March 21 to justice.

Friday's attack followed a protest march led by religious clerics and attended by around 200 in Kabul on Friday against the Koran burning and plans announced by Karzai in February for possible permanent US bases in Afghanistan. The demonstrators, who left from mosques in downtown Kabul after Friday prayers, burned a US flag and stamped on it, shouting "Death to America".