The United States has tried to stem Muslim anger over reports with US Secretary of State Condoleezza Rice promising to punish any offenders.
But the top US military officer, General Richard Myers, chairman of the Joint Chiefs of Staff, said no evidence had been found yet to back allegations that a Koran had been put down a toilet at the Guantanamo Bay camp in Cuba.
MsRice used an appearance before a Senate committee to make a special statement “directly to Muslims in America and throughout the world” on the reported incidents.
“Disrespect for the holy Koran is not now, nor has it ever been, nor will it ever be, tolerated by the United States,” she said.
“We honour the sacred books of all the world’s great religions. Disrespect for the holy Koran is abhorrent to us all.”
Muslims have been enraged by a report that Guantanamo interrogators placed copies of the Koran in a toilet to unsettle prisoners.
Seven people have been killed in protests in Afghanistan and there has also been criticism from Pakistan, a staunch US ally in the war on terrorism.
Meanwhile the Saudi government has urged the US government to carry out a rapid inquiry, saying that if allegations were found to be true, measures should be taken to dissuade against any similar incident in the future.
“The government of Saudi Arabia is closely following, with indignation, media reports of desecration of the holy Koran at Guantanamo,” the official Saudi Press Agency quoted an unidentified Foreign Ministry official as saying.
Saudi Arabia “appeals to the concerned American authorities to carry out a quick investigation in the matter and stresses that in case the reports were true, deterrent measures should be taken against those perpetrators to prevent its recurrence and to protect the sentiments of Muslims all over the world,” the Foreign Ministry official said.
Ms Rice said US military authorities were fully investigating the allegations. “If they are proven true we will take appropriate action.”