A home-grown Islamist militant group was responsible for last month's deadly bomb attack on a restaurant in Pune, a government official said on Tuesday.
The Indian Mujahedeen (IM), a shadowy movement that has claimed attacks in the past, has been identified as responsible for the blast that killed 16 people, including several foreigners, a government source told AFP.
"The fact that the IM was involved has come out during the investigation," the source told AFP, asking not to be named.
The bomb hidden in a bag in the German Bakery in Pune was the first major attack in India since the November 2008 assault on Mumbai, which left 166 dead, and it came soon after India and Pakistan agreed to resume official talks.
The Indian Mujahedeen has claimed several serial blasts in recent years, including in 2008 in the city of Jaipur, when it said it would wage an "open war" against India for supporting the United States.
In the same year, it claimed responsibility for explosions in New Delhi when around 30 people were killed, and also bombings in Ahmedabad when 45 died.
Security services suspect the group may be a front for outfits that have been banned, such as the Students' Islamic Movement of India, which has been linked to militants in Pakistan.
A hitherto unknown Islamist group, which said it had splintered from a larger Pakistan-based network, had initially claimed responsibility for the Pune attack in a telephone call to a newspaper in February.
The Hindu said it had been contacted by someone claiming to be a spokesman for a group called Lashkar-e-Taiba al-Almi, an offshoot of Lashkar-e-Taiba, which said it had carried out the bombing.
Lashkar-e-Taiba is a well-established militant group blamed by India for the Mumbai attacks.
The caller said the Pune attack was in response to India's "refusal" to discuss the disputed region of Kashmir, claimed by Pakistan and India, during their peace talks.
Home Minister P Chidamabaram regularly stresses the danger of attacks by Pakistan-based militants and other extremists from India.
At the weekend, police said they had arrested two men for planning to attack a fuel facility and a shopping centre in Mumbai.