The attackers blew up a truck loaded with explosives in the southern Helmand province where 1,500 Georgian troops are stationed, the ministry said.

The bombing brings to 29 the number of soldiers lost by the former Soviet state in Afghanistan.

It was the second such attack on Georgian troops in Afghanistan in a month. A suicide bomber killed three Georgian soldiers on May 13.

Georgian troops have been in Afghanistan since 2004, a commitment that underscores Tbilisi's ambition to join NATO, despite opposition from neighboring Russia, with which it fought a war in 2008.

With around 1,570 troops in Helmand, Georgia is the largest non-NATO contributor to the International Security Assistance Force (ISAF), the Georgian Defense Ministry says.

According to the website icasualties.org, 3,330 foreign soldiers have been killed in Afghanistan since the US-led war began in 2001.

The increasing number of military casualties in Afghanistan has caused widespread anger in the US and other NATO member states, undermining public support for the Afghan war.

The offensive removed the Taliban from power, but insecurity continues to rise across Afghanistan, despite the presence of thousands of US-led troops.