A few hours after the five serial blasts ripped the national capital killing at least 20 people, the police said they got vital leads in the investigations and traced the email threat by the Indian Mujahideen claiming the blast responsibility to Mumbai.
"We have got vital clues in the serial blasts and investigations are on right track. We hope to crack the case very soon," said Delhi Police spokesman Rajan Bhagat.
According to senior Delhi Police officials, seven people have been detained from Karol Bagh and Connaught Place and raids were being conducted in different parts of the capital.
The police officials said the low intensity bombs had sharpnels and ball bearings to cause maximum devastation.
The investigating agencies have also traced the email sent by Indian Mujahideen, which is now stated to be part of banned terror outfit Students Islamic Movement of India (SIMI), claiming to be behind the blasts to a Mumbai suburb and anti-terror squads were making investigations into it.
The police have beefed up security measures around busy markets and were conducted searches at cinema halls, malls, hospitals, metro stations and crowded areas in the capital till late in the night.