The two, whose names have been withheld, were being questioned by a joint team of intelligence agencies.
A special court on Monday refused bail to 14 suspected Islamic State operatives, arrested from across the country.
According to the sources, the agency filed the charge sheet before District Judge Amar Nath.
The recently busted pan-India terror module was in "constant touch" with people perceived to be close to Abu Bakr al-Baghdadi, the feared leader of the Islamic State, receiving instructions for carrying out explosions at important places ahead of the Republic day.
Eleven suspected ISIS operatives arrested from across the country were today remanded in seven days NIA custody by a Delhi court.
The agency claimed that these accused were trying to "advance the cause of ISIS and establish Caliphate in India".
