A Western security source says unknown armed men stopped the Indians' car at 4:00 pm (1130 GMT) around 10 kilometres (six miles) north of Shahjoy in southeast Afghanistan's troubled Zabul province.
The source, who requested anonymity told the AFP new agency that the Afghan driver of the vehicle was beaten and the armed men made off with the Indians and their car.
Shahjoy, 280 kilometres (175 miles) southwest of Kabul, is in the heart of Zabul province which has been wracked by violence blamed on Taliban fighters.
The Indians were working for the Indian BSC/C and C joint venture firm which is helping to rebuild the important Kabul-Kandahar road.
No further details are immediately available.
Their kidnapping comes less than a week after a Turkish road engineer was released after a month being held captive by Taliban who had demanded the release of fellow combatants held in Afghan jails.