Indian Mujahideen co-founder Yasin Bhatkal and his associate was flown to Delhi by a special plane here this afternoon.
The special plane with Bhatkal and his associate Osadulla Akhtar alias Haddi and NIA officials on board took off from the Jai Prakash Narayan International Airport at 12:38pm.
Earlier, the duo with their faces covered were brought to the airport from the BMP camp under tight security arrangements.
A small group of people raised slogans at the airport demanding capital punishment to Bhatkal and his associate.
The NIA had yesterday obtained a three-day transit remand of Bhatkal and his associate from a Motihari court.
The two, who were brought to Patna from Motihari by road last night, were kept at the Bihar Military Police (BMP) campus near the Airport.
NIA officials interrogated Bhatkal and Akhtar at BMP office again this morning before taking them to national capital.
A joint team of Bihar police and NIA had arrested Bhatkal and Akhtar, carrying a reward of Rs 10 lakh each, from Nahar chowk in Raxual along Indo-Nepal border, around 225 km from the capital town of Patna, yesterday.