Eight foreign employees of the United Nations in Afghanistan have been killed after protesters overran their compound in the northern city of Mazar-i-Sharif: two of the dead were beheaded by attackers who also burned parts of the compound and climbed up blast walls to topple a guard tower, said Lal Mohammad Ahmadzai, a police spokesman for the northern region: over a thousand protesters had flooded into the streets of the normally peaceful city after Friday prayers to denounce the burning of the Koran by a US pastor, and after two or three hours violence broke out.