US Army Staff Sgt. Ashley Morrison, 381st Military Police Company, Task Force Guardian, Indiana National Guard, provides security during a patrol near Bagram Airfield in Parwan province, Afghanistan, April 17, 2012.
The troops were killed Monday when an attacker rammed an explosives-laden motorcycle into their patrol in a village near the airfield. The Taliban has claimed responsibility.
The official was not authorized to discuss the incident publicly so spoke on condition of anonymity.
The attack is the latest a a recent surege of violence acroos Afghanistan, and it comes just days after
A recent Pentagon report said that violence in Afghanistan has increased since a violent two week-long Taliban offensive on the town of Kunduz in September left at least 848 civillians killed or wounded. During the fighting in Kunduz, US warplanes reportedly bombed a Doctors Without Borders hospital.
In addition to Afghanistan's troubles with the Taliban, there have also been reports that ISIS is establishing a foothold in the country.
On November 30, the US Embassy in Afghanistan issued a warning of an "imminent attack" in Kabul within 48 hours. "The security situation in Afghanistan is extremely unstable, and the threat to all US citizens in Afghanistan remains critical," the embassy said.
The next 48 hours passed without incident, but on December 11, a house near Spain's embassy in Kabul, was attacked by gunmen, suicide bombers, and a car bomb, leaving at least seven injured and two dead.