The United States is promising an open investigation into a magazine report that US soldiers desecrated the Koran, but officials say so far they have found nothing to confirm the report. The Newsweek magazine article sparked four days of protests in Afghanistan, where officials say at least eight more people died Friday in anti-US violence. Smaller protests have also been held in other Islamic countries. U.S. State Department spokesman Richard Boucher told VOA Friday the reported desecration of a Koran was very upsetting. He said the government was taking the allegation seriously, and if it was found to be true, those responsible will be punished. The demonstrations began after Newsweek quoted unidentified sources who said US military interrogators put the Muslim holy book in a toilet to upset Islamic detainees at Guantanamo Bay, Cuba.