The two minor track and field athletes returned positive in the tests conducted during the 17th Milo National Inter District Junior Athletics Meet last November in Tirupati, Andhra Pradesh.
Both of them were handed provisional suspension from January 21, the NADA said on Tuesday.
The other two minors comprised a boxer and a volleyball player.
The boxer returned positive in the test conducted during the 65th National School Games (Boxing U-14) Championship in November last year. The boxer was handed provisional suspension on February 6.
The volleyball player also returned positive from the test conducted during the 65th National School Games Championship last year and was provisionally suspended on January 31.
Asian junior hammer throw champion Ashish Jakhar also tested positive and has been placed under provisional suspension. He tested positive at the Services Athletics Championships in Pune last September.