The soldiers were travelling in an armoured vehicle north of the city of Kandahar, part of a convoy supporting a road construction project.
The two wounded soldiers were evacuated to Kandahar Airfield for medical treatment. Both were in stable condition, the US military said in a statement.
Taliban leader captured
Meanwhile, Pakistani officials announced on Thursday that a purported senior figure in the Taliban militia had been captured near the border with Afghanistan.
An intelligence official said Ustad Mohammed Yasir was arrested last week along with another man near the northwestern town of Nowshera.
Interior Minister Aftab Khan Sherpao confirmed the arrest but did not give any details.
Yasir had been a spokesman for fugitive Taliban supreme leader Mullah Omar after the ouster of the hardline government in late 2001.
Pakistan was a main supporter of the Taliban government until it joined the US led war on terrorism after the 11 September 2001 attacks on the United States.
Afghan officials accuse Pakistan of still harbouring Taliban fighters on its soil.