Several hundred demonstrators had gathered outside the U.N. compound in Mazar-e-Sharif to protest the burning of the Muslim holy book - "the Quran"- by a pastor in the U.S. State of Florida 10 days ago.
U.N. Peacekeeping Chief Alain Le Roy briefed the council on details of the attack, which he received from the U.N.’s top diplomat in Afghanistan, Staffan de Mistura, who went immediately to Mazar-e-Sharif to oversee the investigation.
"There was an important demonstration, and part of the demonstrators rushed into our compound with weapons; and they stormed the compound, they put fire on it and they killed several of our staff."
LeRoy told reporters the dead included three civilian staff - a Swede, a Norwegian and a Romanian - as well as four Nepalese guards contracted to protect the compound. He said no Afghan employees were among the dead.
Le Roy said right now the indication is that the attackers were looking to strike an international target.
"We are not sure at all that the U.N. was a target. It happened that U.N. were there, the demonstrations were there. I just discussed myself with SRSG [Special Representative of the Secretary-General] Mr. de Mistura, and his impression as far as now, that the U.N. was not the target. They wanted to take a target, so of course they used this one. They wanted maybe to find an international target and the U.N. was the one here in Mazar-e-Sharif."
He said the U.N. would be temporarily evacuating staff in Mazar-e-Sharif while security there is reviewed. Le Roy also announced that two senior advisers of the Secretary-General, as well as the head of U.N. Security, would leave Friday night for Kabul.
Speaking earlier in Nairobi, U.N. Secretary-General Ban Ki-moon condemned the attack as "outrageous and cowardly" and said it cannot be justified under any circumstances.
And in a statement, the Security Council also strongly condemned the attack and called for the Afghan authorities to bring the perpetrators to justice.