The unidentified aircraft crashed while landing at an airfield in Lashkargah, the capital of restive Helmand province, deputy provincial governor Mullah Amir Akhund told AFP. The cause of the accident was unclear.
"The incident caused casualties in the nomad tents and houses it hit, we are now taking out the wounded and possibly dead people out of the rubble," Khan said.
Deputy provincial police chief Mohammad Ayob Ansari, who was at the crash site, told AFP that a three-year-old child was killed and six Afghan civilians were injured. All were on the ground, he said.
Another three people on board were injured and were evacuated from the crash site, he said.
Ansari said the plane was Russian-built and chartered by a military agency but had no further details.
The airport is small, old and in poor condition, Ansari added.
Police were probing the cause of the crash and trying to identify the plane "but the priority now is to evacuate the people affected by the incident," he said.
Helmand health director Anayatullah Ghafari said he was aware of a woman, three children and two men who were injured and added that they had been taken to a public hospital in Lashkargah.
Helmand has been hard-hit by a wave of violence blamed on remnants of Taliban regime, who were toppled by an US-led offensive in late 2001 after they failed to hand over Osama Bin Laden following the September 11 attacks.