Governor Assadullah Wafa says the planes attacked a village in the province's Sangin district after Taliban fighters sought shelter in noncombatants' homes there.
Wafa said he is sending a delegation to investigate the incident.
The village is near Helmand's strategic Kajaki hydroelectric dam -- an area where NATO forces are conducting a spring offensive against Taliban fighters.
The report comes as foreign forces operating in Afghanistan come under increasing pressure to prevent civilian deaths.
NATO officials pledged to make it a priority in 2007 to avoid noncombatant deaths as they battle Taliban, Al-Qaeda, and insurgent forces more than five years after the U.S.-led military intervention to oust the fundamentalist Taliban regime.
Afghan and UN officials believe that around 50 civilians were killed by foreign forces in the western Herat Province in April. The U.S.-led coalition has said it is investigating that incident.
U.S. Compensation For Jalalabad Killings
On May 8, a U.S. military commander expressed "deep, deep" shame and regret to the families of 19 Afghans killed and 50 others wounded when a Marine Special Operations unit fired on passersby near Jalalabad, in eastern Afghanistan, after their convoy was targeted by a suicide bomber in March.
"The New York Times" reported that Colonel John Nicholson's statement, accompanied by compensation of $2,000 to each of the victims' families, represented the "first formal acknowledgement" by U.S. officials of U.S. wrongdoing in the incident.
A U.S. military vehicle damaged by insurgents near Kandahar (epa)
HOMEGROWN OR IMPORTED? As attacks against Afghan and international forces continue relentlessly, RFE/RL hosted a briefing to discuss the nature of the Afghan insurgency. The discussion featured Marvin Weinbaum, professor emeritus of political science at the University of Illinois at Urbana-Champaign, and RFE/RL Afghanistan analyst Amin Tarzi.
Listen to the entire briefing (about 83 minutes):Real Audio Windows Media
RFE/RL's coverage of Afghanistan
For weekly news and analysis on Afghanistan by e-mail, subscribe to "RFE/RL Afghanistan Report."