UK Bansal, Secretary, Internal Security says: No leads on who is responsible, or on any organisation.

Remember, the government has been careful to state that no single or specific leads were found yet, on who was resposible for the blasts.

What the government says is that...

• 1 kg of ammonium nitrate was used in the Opera House blast, the most powerful.
• 400  to 600 gm of the explosive was used in Zaveri Bazaar
• And 200 gm in Dadar.

... Soon, Vicky Nanjappa's story on Ammonium Nitrate