Kabul, Afghanistan ? As Afghan towns calm after riots that killed at least 15 people, questions remain on why Newsweek’s since-retracted 200-word report that Guantanamo interrogators put a Quran in a toilet triggered such a violent response, when similar claims over the past year did not.

On Tuesday, Afghan President Hamid Karzai’s spokesman charged that “elements from within and outside Afghanistan” manipulated peaceful protests into violence, seeking to spread unrest while Karzai was in Europe — and ahead of his trip to Washington to discuss a long-term strategic relationship.

Afghans’ strong feelings about the Guantanamo prison camp gave an opportunity for “enemies of Afghanistan and for those who are keen to cause destruction in Afghanistan” to instigate riots, spokesman Jawed Ludin told reporters.

Ludin did not name anyone specifically, but it was likely he alluded to neighboring Pakistan. Indignation over the Newsweek story first surfaced in Pakistan at a news conference by Imran Khan, a leading critic of the U.S.-led war on terrorism. Taliban and al-Qaida loyalists also have found refuge among Islamic hard-liners in Pakistan.

Striking a similar note, Gen. Richard Myers, chairman of the Joint Chiefs of Staff, said at the Pentagon last week that the U.S. commander in Afghanistan, Gen. Carl Eichenberry, doubted whether the Newsweek report was behind the violence.

Eichenberry thought the rioting was “more tied up in the political process and the reconciliation process that President Karzai and his Cabinet is conducting in Afghanistan,” Myers said. “He thought it was not at all tied to the article in the magazine.”

The furor caused by the report appeared to embolden former inmates of Guantanamo staying in Pakistan to air more accusations that U.S. personnel abused the Quran.

Abdul Rahim Muslim Dost, a 42-year-old Afghan freed from Guantanamo last month, told the Pakistani network Khyber TV on Monday that an Arab inmate had recounted to him and others in the prison how interrogators threw a Quran to the floor and stepped on it.

Dost’s claims echoed charges made by several released Guantanamo detainees over the past year.

Last August and October, British citizens freed from the prison in Cuba charged abuses by U.S. guards, including throwing their Qurans into the toilet.

Last July, Al-Jazeera satellite television, which is widely watched across the Arab world, carried allegations from a former Guantanamo inmate who said that soldiers at prisons in Afghanistan stomped on a Quran and in one instance “had thrown it into the toilet.”

In January, Kristine Huskey, a lawyer representing Kuwaitis detained at Guantanamo, said they claimed to have been abused and in one case a detainee saw a guard throw a Quran into a toilet.