(CNN) — U.S. troops were among six NATO service members killed in a Monday motorcycle bomb attack in Bagram, Afghanistan, military officials told CNN.
A suicide bomber on a motorbike carried out the attack on a joint patrol of Afghan and coalition forces at about 1:30 p.m. in the Bajawri area of Bagram district, said Waheed Sediqi, a spokesman for the governor of Parwan province.
The area is close to the U.S. base in the Bagram district of northern Parwan province.
“We’re deeply saddened by this loss,” Brig. Gen. Wilson Shoffner said in a statement. “Our heartfelt sympathies go out to the families and friends of those affected in this tragic incident, especially during this holiday season.”
The names of those killed were not immediately released.
The attack remains under investigation, said Col. Michael Lawhorn, a spokesman for NATO’s Operation Resolute Support.
The six people killed Monday bring the tally of NATO service members who have died in Afghanistan this year to 25. The death toll has steadily declined year by year since reaching a peak of 711 in 2010.
The number of U.S. troops in Afghanistan stands at just under 10,000, down from its peak of 100,000 in 2010.
According to NATO, the operation was launched in January “to provide further training, advice and assistance for the Afghan security forces and institutions.” The mission involves 12,000 personnel from NATO and 14 partner nations.
Its central hub is in Bagram/Kabul with “spokes” in Mazar-e Sharif, Herat, Kandahar and Laghman, NATO says.