Vice President Mike Pence, speaking in Wisconsin on Saturday, offered his condolences to the victims’ relatives.
"On my way here I was informed that U.S. service members were killed and wounded in an attack in Afghanistan," Pence said. "The president and I have been briefed; the details of this attack will be forthcoming. But suffice it to say, when heroes fall, Americans grieve. And our thoughts and prayers are with the families of these American heroes."
So called green-on-blue attacks aren’t uncommon in Afghanistan and happen for various reasons. The frequency of attacks spiked in 2012, but have reduced after better vetting practices were put in place, ABC reported.