JABAR, Afghanistan — A NATO airstrike destroyed a mud brick home, killing four generations of an Afghan family — nine people in all — during a firefight between Western troops and militants, Afghan officials and relatives said today.

Militants late Sunday fired on a NATO base in Kapisa province, just north of Kabul. When fighter aircraft returned fire they hit a civilian home, killing five adults and four children between the ages of 6 months and 5 years, said Gulam Nabi, 51, a relative of the victims.

Maj. William Mitchell, a U.S. military spokesman, said officials were looking into the incident. The NATO base in Kapisa is staffed by U.S. forces and sits some 50 miles northeast of Kabul, the capital.

An Associated Press reporter at the scene said a large mud home in a compound of five buildings was destroyed, leaving only exploded bits of mud.

Among those killed were Gulam Nabi's parents, his sister, his nephew, and four of the extended family's youngest children.