He was one of the 20 men India had demanded that Pakistan hand over after the Mumbai terror attacks.

Abdul Karim Tunda, the alleged Lashkar-e-Taiba ideologue whose name figured in India’s list of top-20 most wanted international fugitives, has finally been caught. He was on the run for the past two decades and known to be resident in Pakistan. Tunda’s formal arrest on the Indo-Nepal border on Friday marked the culmination of a complex operation involving the cooperation of Nepali and Indian intelligence agencies.

Though officially the arrest was effected by the Delhi Police Special Cell on “inputs from central intelligence,” well-placed sources told The Hindu that Tunda was actually apprehended by the Nepali authorities after he arrived in Kathmandu on a flight from Karachi and was handed over to the Indian police at the border. He had travelled to Nepal on a Pakistani passport issued in the name of Abdul Quddus on January 23, 2013.

Seventy-year-old Tunda, according to police records, was among the first batches of Indians recruited by Pakistan’s Inter-Services Intelligence to foment terrorism and is suspected to have masterminded over 40 blasts in and outside the Capital in the aftermath of the Babri Masjid demolition in December 1992.

Said to be a master in the configuration of improvised explosive devices using household goods, Tunda over the years allegedly rose up in the LeT hierarchy from a bomb trainer to preacher of terrorism. In Delhi, he is wanted in 21 cases of terror strikes during 1994-98, including the blast outside Police Headquarters at ITO in January 1997 that had left 50 injured. He is also wanted in the 1993 Mumbai serial blasts.

Dressed in a kurta-pyjama, Tunda was arrested by the Special Cell at the Banwasa-Mehendarnagar border with Nepal at 3 p.m. on Friday.

Special Commissioner of Police S.N. Srivastava said that what prompted Tunda to travel to Nepal and what were his future designs are still a matter of investigation. He was produced before a city court on Saturday and remanded in three days’ police custody.

Tunda flew to Nepal days after Pakistan-based LeT chief Hafiz Saeed recently issued threats of another round of terror strikes in India.

He was wrongly believed to have been killed in a blast in Bangladesh capital Dhaka way back in 2000.

Lost his left arm while handling explosives

But Tunda’s name cropped up again in 2005 when Abdul Razzak Masood, an alleged LeT chief coordinator in Dubai arrested by the Special Cell, disclosed that he had met Tunda in Lahore in November-December 2003. He had settled down in the LeT headquarters years ago, married a Pakistani woman, sold perfumes for sustenance and preached at religious and educational institutions, Masood had claimed.

“Tunda was born in 1943 at Chatta Lal Miya behind Delite Cinema in Daryaganj where his father was in the metal moulding trade. Soon thereafter, the family shifted to its native place at Pilkhuwa in neighbouring Ghaziabad. Tunda initially worked as a carpenter, scrap dealer and cloth merchant. At 40, he was initiated into terror activities,” said Mr. Srivastava. While experimenting with explosives, he lost his left arm and was nicknamed “Tunda.”

The police officer alleged that Tunda was also involved in serial bombings at Lucknow, Panipat and Sonepat in Haryana, Ludhiana, Surat, Gulbarga and Hyderabad.

“In Mumbai, Tunda befriended Dr. Jalees Ansari and both floated an outfit named Tanzeem Islah-ul-Muslimeen: Islamic Armed Organisation for the Improvement of Muslims. Another top LeT militant, Azam Ghouri, joined the Tanzeem floated by the Ahl-e-Hadis to avenge the Babri Masjid demolition in 1992,” said the officer.

After Jalees was arrested by a Central Bureau of Investigation team, led by Neeraj Kumar (the former Delhi Police Commissioner) in January 1994, Tunda escaped to Bangladesh where he set up a base and trained locals. He returned in 1996-98 to mastermind blasts in Delhi and other places, the police say. The most devastating of these explosions was the one inside a crowded private bus in West Delhi in December 1997.

Police claim that Tunda attempted another round of serial blasts before the Commonwealth Games 2010, but had to abort the plan as some of his men were arrested. “He has also been associated with Rohingya operatives [of Myanmar] in the past,” the officer said.