Two US civilians and 10 members of Afghanistan's security forces were killed in two separate attacks today as a major international conference took place in Kabul.
Both the attacks happened in the north of the country.
The two civilians died alongside two Afghan soldiers when a local army trainer opened fire at a weapons training centre in a military base near Mazar-e-Sharif, capital of Balkh province.
One foreign soldier and one Afghan soldier were injured in the incident, a statement by the NATO-led International Security Assistance Force (ISAF) said.
"The suspected individual was thought to be an Afghan Army trainer," the statement said, adding that one of two dead Afghans was believed to be the shooter.
A joint investigation by Afghan and ISAF military officials was under way, it said.
The attack came a week after another "rogue" Afghan soldier killed three British troopers and injured four in the southern province of Helmand.
Besides battling the resurgent Taliban fighters, the around 140,000 US and NATO troops are also tasked with training the Afghan security forces. The combined forces also work with Afghan troops in their operations.
Meanwhile, the Taliban killed eight policemen and wounded another in an attack on the district headquarters of Dana Ghori in the northern province of Baghlan on Tuesday, the provincial governor, Munshi Abdul Majeed, said.
Three insurgents were also killed and five injured in the gunbattle, he said.
The attacks happened on the day around 70 international representatives approved key plans to give the Afghan government more control over aid money and also approved a plan to hand over security responsibilities to Afghan forces by 2014.