Pune, March 13 (IANS) A month after a blast in Pune killed 17 people, city Police Commissioner Satyapal Singh Saturday charged the staff of the German Bakery and its customers with 'utter negligence' and said the bag with the bomb had been lying unnoticed for over 90 minutes.

'It was not a few minutes or 10-15 minutes, more than one-and-half hours and yet nobody bothered to notice it... This is sheer carelessness on the part of the people,' he said, addressing a rally of over 1,000 students at the Azad campus here. The event was organised by the Sakal Social Foundation.

According to Singh, the presence of the bag was also brought to the notice of the cashier by some customers of the bakery, but he was 'too busy' in his work to even take note of it or bother to inform the police.

'Barely 20 minutes later, the bomb exploded there. I am sure that if the German Bakery staff and its patrons had exercised more awareness, the blast could have been prevented and so many innocent lives could have been saved,' Singh said.

The pre-Valentine's Day blast Feb 13 in Koregaon Park killed 17 people, including five foreign nationals.

Despite the multi-pronged investigations by several state and central agencies, the investigators seem to have drawn a blank in the motives behind the blast or its perpetrators.

State Anti-Terror Squad (ATS) chief K.P. Raghuvanshi said the investigations are progressing and they hope to crack the case soon.

'We are examining it from all possible angles, nothing is being ruled out. But I will not speculate on whom we suspect. As soon as we are through, it (details) shall be made public,' Raghuvanshi told IANS.

So far, over 100 suspects have been questioned and allowed to go.

Meanwhile, hundreds of Pune residents, including foreigners and students from scores of colleges participated in 'nirbhayta', or fearless, rallies in different parts of the city here Saturday.

The people paid homage to those killed in the blast and took a pledge not to be cowed down by terror threats.