Security agencies ended a meeting at the Delhi Police headquarters in New Delhi on Sunday as they pursued investigations into Saturday's deadly bombings that killed at least 20 people by official count. A police officer said they had "vital clues" and would crack the case soon.
The Delhi Police Special Cell, which battles terrorists, continued to lift forensic evidence at the five bombed sites in Connaught Place, Karol Bagh and Greater Kailash I, keeping them out of bounds for the public.
A senior officer told IANS that Delhi Police had gathered "vital clues" and was confident it would track down the bombers, who are believed to be from the shadowy Islamist terror group Indian Mujahideen.
Investigators believe the attackers had packed the bombs with ammonium nitrate besides shrapnels and ball bearings for maximum impact. But while the bombs killed in Connaught Place and Karol Bagh, no one died in south Delhi's upmarket Greater Kailash-I's M Block Market.
Police sources said a rag picker boy who had seen two men dump a black polythene bag into a dustbin at Connaught Place, just before it exploded, had been taken to the police headquarters to learn more about the bombers.
A guard at the Regal cinema in the same area who caught a suspect was also being spoken to at the police headquarters.
Delhi's Lieutenant Governor, Tajinder Khanna, presided over a meeting of security agencies including key officers from Delhi Police and the Intelligence Bureau.
Simultaneously, police teams searched hotels and guest houses in the Walled City and Karol Bagh areas in a desperate hunt for the elusive bombers who some believe could have been from outside Delhi.
"Our suspicion is about SIMI," an officer said, referring to the outlawed Students Islamic Movement of India, which has been increasingly linked to terror attacks in Indian cities.
A team of policemen is expected to visit Gujarat to talk to Abu Bashir, who the Gujarat Police arrested after calling him the mastermind of the Ahmedabad blasts in July that killed 56 people.
The Indian capital was calm on Sunday. The major markets, however, attracted fewer people. Traffic on the city's roads was sparse.
Government officials said security had been beefed up in busy markets, cinema halls, hospitals and Metro stations.
A police source said that "seven or eight people" were detained on Saturday night.
The serial blasts that rocked Delhi caused mayhem in just 20 minutes.
Five minutes before the first bomb exploded, the Indian Mujahideen sent out email messages to media houses claiming responsibility and warning them about the impending disaster.
All three targeted sites -- Connaught Place, Karol Bagh and Greater Kailash -- are perennially crowded, particularly during weekends. The first two are also among the capital's leading trading hubs.
The maximum damage was inflicted on Karol Bagh, where at least 13 people died and more than 40 were injured.
The police also found and defused three bombs - two in Connaught Place and one near India Gate, a capital landmark whose expansive lawns serve as a popular evening retreat for families.
The Indian Mujahideen had also claimed responsibility for the July bombings in Ahmedabad. The group says it is avenging the "oppression" of Indian Muslims, particularly in Gujarat.
Delhi was last rocked by a terror attack in 2005 when multiple blasts in Sarojini Nagar and Paharganj markets killed 51 people on the eve of the Diwali festival.