Britain's Ministry of Defense said Tuesday the attacker turned his gun on international troops at a base in southern Helmand province and opened fire. Local officials say several other British troops were wounded in the attack.

The NATO command in Afghanistan says the killing Monday is the latest suspected incidence of what officials call "insider attacks."

Insider attacks have been on the on the rise in Afghanistan, leaving more than 60 foreign troops dead in 2012.

Monday's attack also came as Afghan President Hamid Karzai was preparing for talks in Washington later this week with U.S. President Barack Obama on the long-term security agreement between the two nations.