Prime Minister (PM) Manmohan Singh vowed to bring to justice perpetrators of the Mumbai bombings.

"Our task now is to find who the perpetrators of the blasts and how we work together to in order to bring him to justice," said Prime Minister Singh, as quoted by Reuters on Friday (07/15/2011).

Until now, none of the militant group which claims to have launched bomb attacks on Thursday.

The Indian government also has not stated publicly associated who is responsible for three blasts in Mumbai that killed 21 people.

The first bomb explosion occurred in the jewelry store, while another blast occurred in the homes of the elite and the crowd of citizens in the District Dadar, Mumbai.

India's Interior Ministry said police currently being interrogated some members of Indian Mujahideen detained a few days before the blasts in Mumbai.

Indian Mujahideen militant group is quite popular with bomber activity. They've planted a bomb in a restaurant, bus stop and highway.

The group is also suspected of having links with Pakistani militants who attacked the Kashmiris.

The most severe incident in Mumbai bombings occurred in 2008. Bomb attacks that killed 166 at the time residents and fueled tensions between India and Pakistan.