Protests in Palestine, Egypt, Sudan, Pakistan and Indonesia followed demonstrations across much of Afghanistan in the past few days in which 14 people were killed and dozens injured after clashes with police.
Saudi Arabia, Iraq and Syria have registered displeasure at the alleged desecration.
The spreading anger comes after a report published by Newsweek magazine said that US interrogators at Guantanamo Bay desecrated copies of the Quran by leaving them in toilet cubicles and stuffing one down a lavatory.
Friday prayers protest
In Afghanistan, the protests have been the worst anti-US demonstrations since the fall of the Taliban in 2001.
On Friday, protests entered a fourth day in Afghanistan, spreading to new cities across the conservative nation where American troops maintain a heavy presence.
Afghan troops shot dead three people as protesters tried to storm the governor's house in southern Ghazni province, bringing the number of people killed since Tuesday to 14, officials said.
"[Muslim Brotherhood]expresses its extreme anger, condemns and deplores this odious and humiliating act"
Muslim Brotherhood statement
The police chief of Ghazni was shot in the chest, and US forces airflited him to the capital, Kabul, for medical treatment, witnesses and doctors said. Eighteen other people were injured in the clashes.
Fighting with police
Three died when about 1000 people took to the streets near Faizabad, capital of the northeastern Afghan province of Badakshan. Twenty-two people, including three police officers, were injured, and protesters torched the offices of three foreign aid agencies, provincial officials said.
The army opened fire on 300 protesters in the southeastern city of Gardez, killing one and injuring at least three, doctors and officials said. Some protesters were carrying guns, according to the provincial security chief.
Protests broke out for a second day in Kabul, although witnesses said only about 50 people turned out.
Afghan officials have suggested that elements opposed to the US-backed effort to rebuild the war-ravaged country have coordinated the violence.
In Palestine, Aljazeera reported that about 2000 demonstrators from the Jabaliya refugee camp in the northern Gaza Strip held aloft copies of the Quran and Hamas flags as they marched through the streets after Friday prayers.
At the Jabaliya refugee camp in the northern Gaza Strip, about 2000 demonstrators held aloft copies of the Quran and Hamas flags as they marched through the streets in a protest organised by the Islamist resistance group.
Palestinians protest in the
Jabalya refugee camp in Gaza
American and Israeli flags were burned during the demonstration after Friday prayers, while 400 people mounted a similar protest in the West Bank city of Hebron.
Muslim groups incensed
Nizar Rayan, a Hamas political leader, said Palestinian demonstrators were outraged by "the profanation of the Quran by the enemies of God at Guantanamo, and by the Zionist enemies in the prison of occupation".
Egypt's Islamist opposition also condemned the reports and said Arab leaders should share the blame.
"The Muslim Brotherhood has been shaken by news of the desecration of the Quran by American interrogators at Guantanamo," the movement's leader Muhammad Mahdi Akif said on Aljazeera television.
The banned but tolerated group "expresses its extreme anger, firmly condemns and deplores this odious and humiliating act, and calls on the American government to publicly apologise".
"In Guantanamo, the Quran is torn up and thrown in toilets while Muslims don't lift a finger"
Ahmad Abd al-Ghafur al-Samarrai, Iraqi cleric
Calling for the toughest punishment to be meted out on the perpetrators, the oeganisation blamed regional weakness for the reported desecration.
"If it wasn't for Arabs' paralysis and impotence, these criminals would not have committed this act," the group said.
Other parts of the world
One-time US foe, Libya, condemned the "irresponsible and immoral acts", saying they would likely nourish "terrorism".
In Iraq, Sunni and Shia imams alike spoke out against the alleged desecration in their sermons.
"We condemn the desecrations of the Quran carried out by American soldiers at Guantanamo," said Shaikh Abd al-Zahra Suyaidi, a follower of Shia leader Muqtada al-Sadr.
In Palestine, US and Israeli
flags were burned in protest
Sunni cleric Shaikh Ahmad Abd al-Ghafur al-Samarrai said: "In Guantanamo, the Quran is torn up and thrown in toilets while Muslims don't lift a finger."
Saudi Arabia, a staunch US ally but guardian of Islam's holiest places, urged Washington to carry out a speedy investigation and punish those responsible.
"(Riyadh) calls on the competent authorities to implement a swift inquiry into the cases," a Foreign Ministry source said.
"If the cases turn out to be true, the Saudi government underlines the necessity of taking dissuasive measures ... against those responsible to prevent its repetition and to respect Muslims' feelings around the world."
Influential Arab paper
An editorial in the London-based daily Al-Quds al-Arabi said that "the Arab world is totally submissive to the United States".
"Authorities, clerics and official media only react once they have the green light from Washington. From now on, the Arabs are like a corpse. They will not react, even if Makka is occupied," the editorial said.
The director of the London-based Islamic Observatory, a self-proclaimed defender of Muslim rights around the world, poured
scorn on Arab leaders.
"Arab and Muslim rulers are apostates. Their people are scorned, frustrated and tied up," Yasir Sirri said.
Meanwhile, Aljazeera's correspondent in Islamabad, Pakistan, reported that demonstrations were held after the afternoon prayer in major Pakistani cities.
Protesters set government buildings ablaze and called for the departure of US forces from Afghanistan.
Hundreds of Pakistani Muslims burned US flags and effigies of President George Bush in the capital, Islamabad, Pakistan's biggest city, Karachi, its second city, Lahore, and a number of other major towns.
"[This] act of sacrilege has shocked the people of every faith around the world"
Pakistan parliament statement
Demonstrators chanted "Death to America" while speakers at rallies called by an alliance of hardline religious parties demanded the US government punish those involved in the reported desecration of the Muslim holy book.
They were also demonstrating partly because of a controversial cartoon in The Washington Times newspaper that portrayed Pakistan as America's dog in the "war on terror" hunting down al-Qaida, Aljazeera reported.
The lower house of the Pakistani parliament, in a unanimous resolution on Friday, condemned the "shameful act" of desecration and demanded an inquiry by the United States to bring the perpetrators to justice.
"The reported act of sacrilege has shocked the people of every faith all around the world," the resolution signed by both the treasury and the opposition members said.
The treatment of prisoners
has sparked global outrage
The US has responded by promising an inquiry over the alleged abuses.
US Secretary of State Condoleezza Rice used an appearance before a Senate committee on Thursday to make a special statement "directly to Muslims in America and throughout the world" on the reported incidents.
"Disrespect for the holy Quran is not now, nor has it ever been, nor will it ever be, tolerated by the United States," she said.