A Taliban car bomb struck a NATO military convoy on Saturday, killing three foreign soldiers and two coalition civilian workers in the deadliest attack on Western forces this year.

A Taliban car bomb struck a NATO military convoy on Saturday, killing three foreign soldiers and two coalition civilian workers in the deadliest attack on Western forces this year.

The blast occurred in the Zabul province, where American and Romanian troops are based, according to the International Security Assistance Force (ISAF), which did not disclose the nationalities of the soldiers in line with policy.

"Three International Security Assistance Force (ISAF) service members and two coalition civilians died following an improvised explosive device attack in southern Afghanistan today," the force said in a statement.

An ISAF spokesman in Kabul confirmed the blast was a car bomb targeting a military patrol, adding that there were also two Afghan civilian casualties.

Taliban insurgents who have been waging a tough insurgency since the toppling of their regime in 2001, claimed credit for the deadly strike on their website, which they said happened near a newly constructed hospital.

The attack comes as US led coalition forces this year wind down its operation in the country ahead of a scheduled full withdrawal of 100,000 remaining troops in 2014.