KABUL, Afghanistan (AP) -- A helicopter crash killed two NATO service members in eastern Afghanistan on Monday, and a third died in an insurgent attack in the south, the U.S.-led coalition said.

The deaths raised the number of NATO troops who have been killed in Afghanistan this year to 172. NATO is aiming to withdraw its combat forces by the end of 2014 and turn security responsibility over to the Afghans.

Authorities were investigating the cause of the crash, but initial reports indicate there was no enemy activity in the area at the time the helicopter went down, the coalition said.

No further details about the crash in the east or the insurgent attack in the south were released.

A second coalition aircraft crashed Monday in eastern Afghanistan. No fatalities were reported. The coalition said this incident was not related to the helicopter crash, which also occurred in the east.

Officials are trying to determine why the aircraft went down. Initial reports indicate there was no enemy activity in the area. There were no reports of civilians being harmed or property damaged because of the crash. The coalition transported the aircraft's crew and passengers to a nearby base for evaluation.

Elsewhere in Afghanistan, gunmen killed a member of the community council in southern Helmand province's Sangin district Monday, the provincial government said.

Haji Raz Mohammad was headed to the district governor's office when he was attacked, the government said. Authorities were searching for the gunmen.

A roadside bomb killed seven people in northeastern Baghlan province Monday, including three civilians and four members of the Afghan Local Police, said provincial police chief Gen. Asadullah Sherzad. The Afghan Local Police is a government-sponsored militia that works alongside the Afghan army and national police, Sherzad said.