Oct. 16: Central agencies this evening found as many as 30 home-made bombs in a Burdwan house that had been searched by Bengal police eight days ago.

The discovery by the National Investigation Agency (NIA) and the National Security Guard (NSG) is a stinging slap in the face of the Mamata Banerjee government that had opposed a central probe into the Burdwan blast whose ramifications are widening by the day.

The cache of explosive devices was found in the house of Rezaul Karim, about whom investigators had come to know through a mobile number scribbled on the palm of Abdul Hakim, who survived the October 2 blast with injuries. On Wednesday, The Telegraphhad reported about the discovery of the number on the palm.

Rezaul (neighbours referred to him as Rezaul Sheikh) was staying at the house on Badshahi Road in Burdwan town at the time of the blast and is now at large.

A joint team of the CID and Bengal police had searched the same house on October 8 but had found only two knives and some religious leaflets.

Asked why the state team could not locate the bombs, a CID officer said: “At that point of time, we were more focused on interrogating the two arrested women and another suspect. On that day, the search was carried out for about 15 minutes in that house.”

S.R. Mishra, the special superintendent of the CID who had led the search in the house, took a call from this newspaper but said “wrong number”. Home secretary Basudeb Banerjee disconnected the call. Director-general of state police G.M.P. Reddy did not take calls.

Theoretically, the cache could have been placed in the house after the October 8 search also, although there is no such indication so far. But even such a turn would not absolve the local police — a CID official said no guard had been posted outside the house after the October 8 search. A glaring omission, considering the state government was insisting that it was equipped to probe the case and there was no need for an NIA investigation.

This evening, ironically, the sack containing the bombs was noticed by a sub-inspector of Burdwan police.

An NIA team had entered the single-storey house around 5.30pm and searched it for about an hour and a half. The sack was found behind a false ceiling of a bathroom.

“The sack was noticed by a sub-inspector of Burdwan police who are assisting us. We suspected there might be explosives inside the sack. We then called the NSG,” an NIA official said.

An NSG team was then at the Khagragarh blast site, less than a kilometre away. The team proceeded to Rezaul’s house with two sniffer dogs.

“After the NSG team arrived we asked onlookers outside the house to move away. After the explosives were detected, a matador van was called with sandbags in it. The devices were put inside a bag by the NSG and taken away,” the official said.

The NSG’s subsequent action was also in contrast with the haste with which Bengal police had detonated 59 bombs and 55 grenades found at the blast-hit Burdwan flat on October 2. The hasty detonation had triggered allegations of evidence tampering.

The NSG has also taken the cache to the Damodar riverbank but the detonation was not carried out today. It will be done only after gathering forensic evidence.

“We will get forensic samples by this evening or tomorrow, after which we could make some connections,” NSG director-general Jayanta Narayan Choudhury told The Telegraph in New Delhi.

“The devices seized today match the make of the IEDs found at the blast site on October 2,” another official said.

The devices are four-inch-long galvanised iron pipes packed with explosives and fitted with a safety catch to keep them from accidentally exploding while in transit.

NIA sources said that of the 30 devices, four were half-finished and yet to be stuffed with explosives. “From the unfinished IEDs, it appears that someone left the place in a hurry,” an NIA official said.