You could call him India’s Osama bin Laden: his whereabouts unknown, his shadowy stamp on a series of terrorist attacks, and his public messages mocking the security establishment and threatening more bloodshed.
Abdul Subhan Qureshi, a skinny, convent-educated, 36-year-old computer-savvy and smooth-talking bomb maker, is currently the country’s most wanted man.
Qureshi is accused in a series of bombings that have killed more than 140 people this year, the latest on Saturday in New Delhi that killed 23 people.
Qureshi first came into notice after the Mumbai blasts in 2006 and has been missing since. But his name cropped up in every big terror strike after that — Jaipur, Bangalore, Ahmedabad and now Delhi.
And it was becoming increasingly clear that a well-entrenched terror network is already in place across the country, with the ability to make, deploy and set off homemade bombs at will.
As police investigated the blasts, a new threat came in a phone call: the next target would be Mumbai.
Amid mounting criticism over the government’s apparent inability to deal with terror, top security officials met in New Delhi on Sunday to discuss new ideas.
Investigators believe Qureshi is the man signing off terror e-mails as "Al-Arbi", a writer whose ways are getting sharper: the use of unsecured wireless connections, sending a Windows Media Video file - a compressed format for transferring graphic files through the Internet - on Saturday apart from regular PDF versions. It is not known why it was sent in two formats.
His language is also changing with smart one-liners: "Eye for an eye: The dust will never settle down"; police continue to "mess with us"; We "will continue to punish you even before your earlier wounds have healed".
And in March this year, police nearly captured him.
That was when officers arrested terror suspect Safdar Nagori, then the chief of the Students Islamic Movement of India.
"We had delayed the arrests of Nagori and his aides since we were waiting for Qureshi to arrive," Indore's inspector-general Anil Kumar told Hindustan Times. He did, but returned from the railway station after a call from a public phone booth to Nagori's aides aroused his suspicion.
Rajasthan Police has in its custody Qureshi's senior aide Shahbaz Hussein, a top SIMI leader, who reportedly told police that Qureshi is the man sending the Indian Mujahideen e-mails. He has told Rajasthan police "Qureshi likes writing long e-mails, mocking and ridiculing (others), and uses anecdotes".
Qureshi completed his 10th Standard from a school in Mumbai's Byculla neighbourhood and worked for a few years with a direct sales agency of a major Indian IT firm. He then allegedly joined SIMI in 1998.
Saturday's terror e-mail also threatened to attack Mumbai, the city where it originated, and where the threat was repeated on Sunday. The Air India office in Mumbai received a call from a Bangalore-based mobile number.
"The caller in Hindi said that Mumbai would be bombed," said Jitendra Bhargava, Air India spokesperson.
In New Delhi, another man emerged on Sunday who had apparently seen the attackers. Police were questioning auto rickshaw driver Mool Chand who ferried one of the bombers from Paharganj to Beadonpura in Gaffar Market, where the first of the five explosions occurred on Saturday.
"Moolchand told us that the suspected bomber was sporting a light beard and was in his mid twenties and 5'8'' tall," a senior police officer said.
The passenger got down without paying, leaving his bag near the rickshaw's CNG kit. Minutes later, the bomb blew up, but the driver was away from the vehicle, in an argument with a rickshaw puller that saved his life.
Police said they had also detained and were questioning the owner of the bicycle on which one of the two bombs that exploded in M Block market at Greater Kailash exploded.
Crowds were thinner at the GK-1 market on Sunday, but there were no leftovers from the attacks - except two torn banners at the explosion sites.
Twenty-year-old Lucky, who works in a cosmetics shop in Greater Kailash-1, seemed trying to cheer up the entire city as he said: "Whatever had to happen, has happened. Why fear now?"
(With inputs from Neelam Pandey, Nivedita Khandekar and Moushumi Das Gupta)