Kabul: At least five Afghans were shot dead and dozens wounded on Wednesday in clashes between police and demonstrators protesting over the burning of the Koran at a US-run military base, officials said.

In the capital Kabul and in provinces to the east, north and south of the capital, furious Afghans took to the streets screaming "Death to America", throwing rocks and setting fire to shops and vehicles as gunshots rang out.

In the eastern city Jalalabad, students set fire to an effigy of President Barack Obama, while the US embassy in Kabul declared it was on lockdown.

In Kabul, hundreds of people poured onto the Jalalabad road, throwing stones at US military base Camp Phoenix, where troops guarding the base fired into the air and black smoke from burning tyres rose.

Afghanistan is a deeply religious country where slights against Islam have frequently provoked violent protests and Afghans were incensed that any Western troops could be so insensitive, 10 years after the 2001 US-led invasion.

The US commander in Afghanistan, General John Allen, apologised and ordered an investigation into the incident, admitting that religious materials, including Korans "were inadvertently taken to an incineration facility".

He also ordered that all troops would be trained in the "proper handling of religious materials no later than March 3".

US Defence Secretary Leon Panetta also apologised, saying that he and Allen "disapprove of such conduct in the strongest possible terms" and promising to "take all steps necessary and appropriate so that this never happens again".

UN terms Quran burning a sad mistake

The UN on Wednesday termed the burning of the Quran and other religious materials in Afghanistan by US-led international forces as a "sad mistake" and expressed confidence that those behind the incident will be held accountable.

Protests had erupted in Afghanistan over reports that the UN-mandated International Security Assistance Force (ISAF) troops had burned copies of the holy book along with other religious material, at the Bagram base, one of the largest US bases in Afghanistan.

In the wake of the incident, Special Representative of the Secretary-General (SRSG) for Afghanistan Jan Kubis met Chairman of the Ulema Council of Afghanistan with Maulawi Qiyamuddin Kashaaf in Kabul, according to a UN statement here.

The SRSG "expressed his full confidence that ISAF will rapidly conclude the investigation, take appropriate follow-up action as soon as possible and move quickly to hold people behind this incident accountable."

Kubis told Maulawi Kashaaf that he shared concerns of the people of Afghanistan regarding this "sad mistake that hurts the religious feelings of the people."

He stressed that the United Nations deeply respects the Islamic faith, traditions and culture of Afghanistan.

Kubis noted that US General John Allen, the top commander of American and NATO forces in Afghanistan, had apologised to the people and authorities in Afghanistan and ordered an investigation into the incident, which has sparked outrage and massive protests in the country.

Led by Defence Secretary Leon Panetta, the US also apologised to the people of Afghanistan on the "inappropriate treatment" of the holy Quran.

The State Department termed it as a "horrific" incident.