At least eight foreign UN workers and four others have been killed in an attack on a UN compound in the Afghan city of Mazar-e Sharif, officials say. The violence happened during a protest over the burning of the Koran in a US church last month.
Witnesses said hundreds of people were protesting peacefully in the city when the scene suddenly turned violent. A local police spokesman told the BBC the city was now under control and a number of people had been arrested.
The UN has confirmed its workers were killed but has not said how many - it said the situation remained "confusing".
"We are currently working to ascertain all the facts and take care of all our staff," said spokesman Dan McNorton.
UN officials quoted by Reuters warned that the death toll could rise and added that those killed included foreign and local staff, UN guards and Nepalese Gurkha soldiers hired to protect the compound.
UN Secretary General Ban Ki-moon described it as "an outrageous and cowardly attack".