Afghan Taliban bomber kills six NATO troops as violence rises

A motorcycle-riding Taliban suicide bomber killed six NATO soldiers near Kabul today, in a brazen attack as the resurgent militant group battled to seize a key southern district in Afghanistan's opium-growing heartland.

The military coalition did not disclose the nationality of the soldiers killed in the attack, which highlights a worsening security situation a year after the NATO combat mission ended.

The Taliban claimed responsibility for the attack near Bagram, the largest US military base in Afghanistan, during a joint patrol of NATO and Afghan forces.

"Six (NATO) service members died as a result of a vehicle-borne improvised explosive device attack," the US-led coalition said in a statement, adding that three others were wounded.

The bombing marks one of the deadliest attacks on foreign troops in Afghanistan this year and coincides with a fierce militant offensive to capture the strategic district of Sangin in Helmand province.

Local residents reported crippling food shortages in the district, long seen as a hornet's nest of insurgent activity, after the Taliban began storming government buildings yesterday.

"The Taliban have captured the police headquarters, the governor's office as well as the intelligence agency building in Sangin," deputy Helmand governor Mohammad Jan Rasoolyar told AFP.

"Fighting is escalating in the district," he said, claiming the number of soldiers killed in clashes is "unbelievably high".

Rasoolyar's comments come a day after he posted a desperate plea on Facebook to President Ashraf Ghani, warning the entire province was at risk of falling to the Taliban.

The grim assessment bore striking similarities to the security situation that led to the brief fall of the northern city of Kunduz in September - the biggest Taliban victory in 14 years of war.

The fall of Helmand would deal another stinging blow to Afghan forces who have struggled to rein in the ascendant insurgency without the full backing of NATO forces.

The government in Kabul said reinforcements had been dispatched to Sangin, while strongly denying that the district was at risk of being captured.

But trapped residents said that roads to Sangin had been heavily mined by insurgents and exhausted soldiers besieged in government buildings were begging for food rations.