Members of the Afghan national police (file photo)
An Afghan policeman has shot dead an American soldier and wounded three others in the southern province of Helmand.
A member of the Afghan national police opened fire on the Americans on Thursday during a full scale scuffle in the provincial capital city of Lashkar Gah, located about 555 kilometers (344 miles) south of Kabul, a Press TV correspondent reported.
The shooting marks the second incident of its kind in less than a month.
On April 27, a veteran Afghan army pilot opened fire on foreign troops at Kabul airport, killing eight US-led soldiers and a contractor.
Several US-led foreign soldiers and Afghan troops were also wounded in the incident. The Afghan pilot was shot dead at the scene.
Afghans have become increasingly angry over the continued US-led occupation of their country, which also affects Afghan police and army ranks.
NATO troops have recently come under a number of assaults by disgruntled Afghan security forces with some of the attacks causing multiple fatalities among the US-led forces.
A total of 168 US-led foreign troops have been killed in Afghanistan so far this year.
The deadly incidents come as Taliban militants are believed to have been making inroads in different parts of Afghanistan.
The surge in violence comes despite the presence of about 150,000 foreign troops in the country.
The US-led invasion took place in 2001 with the official objective of curbing militancy and bringing peace and stability to Afghanistan.
Anti-war groups have highlighted the fact that Afghanistan still remains unstable 10 years after the invasion.