The worst anti-US demonstrations since the fall of the Taliban in 2001 entered a fourth day in Afghanistan, spreading to new cities across the nation where American troops maintain a heavy presence.

Afghan troops shot dead three people as protesters tried to storm the governor’s house in the southern Ghazni province, bringing the number of people killed since Tuesday to 14, officials said. Another three died when around 1,000 people took to the streets near Faizabad.

Afghan officials have suggested that elements opposed to the US-backed effort to rebuild the war-ravaged country have co-ordinated the violence.

The US has promised an inquiry and action against soldiers at the US detention centre at Guantanamo. According to Newsweek magazine they defiled copies of the Muslim holy book by leaving them in toilet cubicles and stuffing one down a lavatory to rattle Muslim prisoners.

US Secretary of State Condoleezza Rice used an appearance before a Senate committee on Thursday to make a special statement to Muslims in America and across the world, and also promised a full investigation.

Muslims believe that the Koran contains the actual words of God.

In neighbouring Pakistan, a key ally in what the US calls its war on terror, hundreds of Islamic hardliners burned US flags and effigies of President George W. Bush, witnesses said.

Demonstrators in several cities, including the capital Islamabad, Karachi and Lahore, chanted “Death to America” while speakers at rallies called by an alliance of religious parties demanded the US government punish those involved in the reported desecration of the Muslim holy book.

About 6,000 Afghan refugees also staged a demonstration in a camp near the conservative north-western city of Peshawar, before dispersing peacefully.

Jakarta, capital of the world’s most populous Muslim nation Indonesia, saw a rally at a mosque by hundreds of people protesting against the alleged sacrilege.

Students in the Indonesian city of Makassar on Sulawesi Island took to the streets and searched hotels and the airport for any Americans, Detikcom news portal reported. No Americans were found.

At the Jabaliya refugee camp in the northern Gaza Strip, around 2,000 Palestinian demonstrators held aloft copies of the Koran and Hamas flags as they marched through the streets in a protest organised by the radical Islamist group.

American and Israeli flags were burnt during the demonstration following the main weekly Muslim prayers, while 400 mounted a similar protest in the West Bank city of Hebron.

Muslim Arabs from Egypt, Libya, Saudi Arabia and Iraq also expressed anger, both with Washington and their own leaders for their impotence in the face of the alleged desecration.