Afghan officials said several women and children died while they were asleep when a bomb landed on their tent in Zabul's Naw Bahar district.
"The figure I have for the civilian death toll is at least eight," Muhammad Umar, Zabul's deputy governor said.
Muhammad Gul Neyazi, a top Taliban commander was also reportedly killed in the raid together with a friend.
"The Taliban commander and his friend were apparently using a satellite phone, the signal of which was detected by American planes when they carried out the attack," Umar said.
The air strike was part of Operation Mountain Viper, launched by US-led troops in August in response to the presence of hundreds of Taliban fighters in the provinces of Zabul and Uruzgan.
A US military spokesman however said that he had no information as yet about the civilian casualties.
Earlier this year an Afghan woman lost all her nine children when blundering US soldiers sent a laser-guided missile into a home in Bermil village near Shkin in the belief it was a Taliban stronghold.
Two other children perished in the blast as villagers were beaten back by US soldiers as they attempted to rescue those trapped inside the house.
The parents of the 11 dead children were given an apology and a total of $11,000 by a senior US military officer several days later who was escorted by a 50-strong armed guard when he visited the village near the Pakistan-Afghan border.