US officials say most of ISIS fighters have died on the battlefield. Smugglers along the Syria-Turkey border say many have escaped.
Monday's massive arrest came a day after two boats carrying an estimated 600 Bangladeshi and Rohingya refugees were rescued by fishermen and towed to Indonesian soil.
Mohammed Ali Malek is accused of kidnapping and multiple homicide. His boat capsized in the Mediterranean on Sunday, killing at least 650 migrants.
The encounter took place in remote forests near Tirupati, Andhra Pradesh.
A group of smugglers were caught on a remote video surveillance system using a catapult to launch marijuana over the border.