Police sources said that four persons have been detained for questioning in connection with Friday's low-intensity bomb blast at The Rameshwaram Cafe.
Shoaib Ahmed Mirza alias Chhotu (35), a resident of Hubbali city in Karnataka, is the fifth person to be arrested in the case, they said.
Eight days after it was shattered by a blast that left 10 persons injured, The Rameshwaram Cafe in Bengaluru started serving its loyal customers once again on Saturday, throwing open the eatery to the public with heightened security measures.
The police got some vital clues in the past two days, which were promising, he told reporters in Bengaluru.
At least nine people were injured when a blast took place at Rameshwaram Cafe in Brookfield in East Bengaluru on March 1.
The explosion took place at Rameshwaram Cafe in Brookefield in East Bengaluru on Friday. A man wearing a cap, mask and glasses is the prime suspect in the case and is still untraceable,
At this moment it is not possible to say whether any organisation or an individual was involved, the home minister said. There were certain theories during his visit to the cafe on Friday night, expressing suspicion that someone might have done it out of 'heartburn', unable to digest the cafe's success and expansion.
The NIA had arrested Mussavir Hussain Shazib and Adbul Matheen Ahmed Taahaa from Kolkata for their alleged role in March 1 blast at Rameshwaram Cafe here, which left 10 people injured.
Speaking to reporters in Bengaluru, he said no one has suffered serious injuries and the injured -- both staff and customers -- are being treated in hospital.
Asked whether it was a terrorist act, the CM said, it is not known and investigations are on.
What about Uttar Pradesh Pradesh, Rajasthan, Delhi, Gujarat and Bihar? Mamata asked.
In a major breakthrough, the NIA had on Wednesday arrested Muzammil Shareef, the key conspirator in the blast case.
Mussavir Hussain Shazib and Adbul Matheen Ahmed Taahaa were traced to their hideout near Kolkata and apprehended by an NIA team, they said.