"If Delhi Police has taken Fasih into custody, we will also be seeking his custody as he is involved in the Chinnaswamy Stadium blasts", Joint Commissioner of Police (Crime) B Dayanand told PTI.
Fasih, who was in detention for five months in Saudi Arabia, was taken into custody at Delhi airport on his arrival from the Gulf.
India had sought his deportation and also got an Interpol Red Corner notice issued against him.
Believed to be a member of the banned Indian Mujahideen, Bihar-born Fasih, an engineer, is allegedly involved in the Chinnaswamy Stadium blasts in Bangalore and the shooting near Jama Masjid (Delhi), both in 2010, and is wanted by Delhi and Bangalore police.