Abdul Karim got the sobriquet Tunda after he lost his forearm while making a bomb. In 1993, he was involved in the Mumbai serial train blasts. He was most active between 1996 and 1998 during which time he set off blasts in Delhi and serial blasts in UP. He was allegedly involved in the bomb blast outside the Delhi police headquarters and Lajpat Nagar in mid-1990. He has also been involved in serial blasts on trains in Hyderabad, Gulbarga, Surat and Lucknow.
Tunda carried out 24 explosions in Delhi, five in Haryana and three in UP. He trained young indoctrinated youths in bombs-making with locally available materials like urea, nitric acid, potassium chloride, nitrobenzene and sugar and planting them at crowded places to cause the maximum casualties. In March 1985, while Abdul Karim was in Mumbai in connection with trade, there were communal riots in Bhiwandi.
Tunda met and befriended Dr Jalees Ansari and constituted their own Tanzeem Islah-ul-Muslimeen (Islamic Armed Organisation for the Improvement of Muslims). Another top LeT militant, Azam Ghouri, had joined the tanzeem floated by Ahl-e-Hadis to avenge the Babri Masjid demolition.
Tunda and Ansari had, in 1993, set off a series of explosions in Mumbai and Hyderabad and seven separate bomb blasts on trains. After Jalees’ arrest in January 1994, Tunda fled to Dhaka, Bangladesh. In Dhaka, Tunda started imparting training to jihadi elements in bomb-making. He also stayed in Pakistan, where he is known to have imparted training on fabrication of lED and other explosives to mujahids, who are sent to India from Pakistan for jihad.
He returned from Dhaka to India to mastermind the deadly 1996-98 blasts. In almost all the blasts in Delhi in 1996-98, Tunda’s men, who were from Pakistan and Bangladesh, had detonated bombs using pencil batteries. The most devastating of these blasts was in a crowded private bus at Punjabi Bagh in New Delhi in December 1997. The blast occurred when the bus, running between Ajmeri Gate and Nangloi, reached Rampura in Punjabi Bagh, killing four commuters and injuring 24 others.
In 1996, an Interpol red-corner notice was issued against him. In 2000, intelligence agencies got reports that he was killed in Bangladesh. However, in 2005 Tunda returned on the radar of intelligence agencies after the special cell of the Delhi police arrested Abdul Razzak Masood, an alleged LeT chief coordinator in Dubai (UAE), who disclosed that Tunda was alive and he had met him in Lahore in December 2003. In 2006, the Kenyan police claimed to have arrested Tunda which was subsequently claimed to be a case of mistaken identity.
The man they had arrested was a UK national.