Nato soldier dies in Afghanistan 'insider attack'

A member of the Nato-led forces has been shot dead by a man in Afghan army uniform, military officials say.

The assailant was also killed during the attack, which took place in southern Afghanistan, they added.

There has been a sharp rise in so-called insider attacks against local forces and Nato troops in Afghanistan.

The attack came hours before President Karzai was due in the US for a visit seen as key to the future of the American presence in Afghanistan.

An investigation is under way to determine if the attacker had links to insurgents, the International Security Assistance Force (Isaf) said in a statement on Tuesday.

Military commanders refer to such rogue attacks as "green-on-blue" - green for Afghan forces and blue for the Nato coalition.

Mr Karzai's visit comes days after a drone attack that killed Pakistan militant leader Mullah Nazir, who was accused of sending fighters to Afghanistan to support the Taliban.

Meanwhile Mr Karzai has held back from signing a long-term binding security agreement with the US, amid fears that Afghan sovereignty is being undermined.

He is unwilling to grant US soldiers immunity from prosecution and is unhappy that Afghans are still being held in US-run military prisons on Afghan soil, our correspondent adds.

Nato forces are committed to training Afghan security forces before foreign combat troops pull out.Nat