NATO troops have killed an Afghan soldier who tried to gun down coalition service members at a military base in eastern Afghanistan.

A NATO spokesman says no coalition troops were killed in the attack Thursday in Laghman province, but declined to say if any were wounded.

The shooting is the second apparent attack by Afghan forces on their foreign counterparts this week. NATO said Tuesday two gunmen wearing Afghan National Army uniforms killed a NATO soldier.

So far this year, there have been at least 25 so-called “green-on-blue” (reference to uniforms) attacks in which foreign troops have been killed by Afghan soldiers or insurgents disguised in their uniforms.