Hundreds of US troops locked in fiercest Afghan battle for nearly a year

Hundreds of American soldiers, backed by B-1 bombers and Apache helicopters, were locked in their largest and fiercest battle in Afghanistan for nearly a year yesterday.

As Washington pushed forward with preparations for war against Iraq, the upsurge in fighting served as a reminder that its business in Afghanistan, begun in the aftermath of 11 September, is not over.

American officials told reporters that the fighting in hills near the Pakistan border was their biggest engagement with armed opponents since "Operation Anaconda", when 1,500 American troops spent eight days trying to winkle out hundreds of Taliban and al-Qa'ida fighters from mountain caves in eastern Afghanistan.

The battle yesterday saw the American forces call in B-1 bombers, AC-130 gunships, F-16s and Apache helicopters in an attempt to crush a large band of fighters, who American intelligence analysts believe are loyal to the former Afghan prime minister Gulbuddin Hekmatyar – a man who fought in the American-backed mujahedin against the occupying Soviet forces in the 1980s.

Norwegian warplanes joined yesterday's bombardment, dropping their first bombs since they flew from British bases to attack Nazi positions in German-occupied Norway in the Second World War. According to Colonel Roger King, a US military spokesman, up to 350 troops – mainly Americans from the special forces and 82nd Airborne Division but some allied Afghan militiamen – were taking part in the battle against an estimated 80 armed followers of Hekmatyar, an ethnic Pashtun and Sunni Muslim fundamentalist.

The Americans believe Hekmatyar and his Hezb-e-Islami militia – who are violently opposed to the government of Hamid Karzai – have been forging ties with elements of al- Qa'ida and Taliban to wage war against America and its friends. The Taliban has been regrouping in southern and eastern parts of the country, from where it has mounted regular, usually small, attacks on US and Afghan government positions. It killed an American army sergeant last month.

Col King said at the US Army's headquarters at Bagram that warplanes and bombers were in action for more than 12 hours, dropping 2,000lb bombs and firing several smaller guided missiles. Reports suggested that the fighting began when Apache helicopters were fired on as they followed up an informant's tip-off that there was a large group of militants on a mountain about 15 miles north of the town of Spin Boldak.

Col King said at least 18 militants had been killed but there were no casualties from the US-led coalition forces. Asked how long the fighting would go on, the colonel replied: "I would be very, very hesitant to put a deadline. There is a lot of ground to cover. It's a relatively large area and it is rough terrain. It could take a considerable period of time."

There have been reports from United Nations officials that al-Qa'ida and Taliban fighters have set up mobile military training units near the Pakistan border. Other reports suggest that Hekmatyar is organising suicide squads. Matters are further complicated by the depth of anti-American and pro-Taliban sentiment across the border in Pakistan – including within the Pakistani security forces with whom the US is supposed to be jointly waging the "war on terror".