NATO says three coalition troops were killed Monday by Afghan security forces in two separate incidents.
In one incident Monday, two British service members were killed by an Afghan soldier in front of the main gate of a joint civilian-military base in Hilmand province.
Hours later, a US soldier was killed in a shooting incident in eastern Afghanistan. NATO says the soldier was shot by a member of the Afghan local police while approaching a police checkpoint.
More than one in six of the 91 foreign soldiers to have died in the country in 2012 has been killed in so-called "green-on-blue"attacks in which Afghan forces have turned their weapons on their foreign partners.
Deadly protests raged around the nation for six days — the most visible example of a deep-seated resentment bred by what Afghans view is a general lack of respect for their culture and religion.